Re: Re: Is QPCR Better

November 26, 2006

So, Quantitative PCR tests the genetic material currently in the airfor its species of origin, Right. Including large fragments as well as sub-micron mold fragments.

Testing can be Air or bulk or dust

the culture methods grows some subset ofthe viable spores that are in a given sample of air taken at aspecific time, and then counts the mold that grows, microscopically,without speciation,

Culture does speciate very well. It is just not reliable providing quantitative numbers compared to QPCR.

and the spore testing (Air-O-Cell, Zeflon, etc)method analyzes the visible spores that are in the air at that time byexamining them under a microscope, but it ignores all the particulatematter completely?

Almost right. Most labs will give you an indication of the large hyphal fragments along with the spores. But they don't "see" mold microparticles which can also be affecting someone's health as they can contain mold toxins.

Rosen, Ph.D.

Re: Re: Is QPCR Better

So, Quantitative PCR tests the genetic material currently in the airfor its species of origin, the culture methods grows some subset ofthe viable spores that are in a given sample of air taken at aspecific time, and then counts the mold that grows, microscopically,without speciation, and the spore testing (Air-O-Cell, Zeflon, etc)method analyzes the visible spores that are in the air at that time byexamining them under a microscope, but it ignores all the particulatematter completely?> ,>> "As many of you may know, several recent scientific studies have looked> at species analysis from culture testing and found that they are pretty> much random when compared to DNA profiling of the samples (called> Quantitative PCR). Therefore culture testing for speciation is of

no> value.">> Can you provide references for this statement? Since QPCR only> analyzes for some 30+ species, I have difficulty with this statement.> Further, culturable methods used in microbiological diagnosis of mold> infections in people have proven to be more than adequate from many> years. This QPCR claim is in direct conflict with medical research> methods.>> Further, at this point in time, there is no published scientific> evidence showing that QPCR has a stronger (higher correlation> coefficient) to mold related symptoms or disease, than any of the other> test methods.>> The published research history showing a relationship between> dampness, mold and respiratory symptoms was well established in many> studies in the EU, almost 10 years ago. These studies were recently> duplicated in the US. However, this was not new

information.>> There have also been studies in Germany and Canada that correlated> culturable levels with symptoms. Most other studies relate also> culturable levels to symptoms. This is why all of the mold exposure> standards in other countries are set in culturable levels.>> The only guideline on total spore concentrations is the AAAAI table.> However, note that this table drastically changed in 1992, when AAAAI> switch to Burhard from the Rot o Rod samplers.>> There is also no study that has proven that total spore sampling is any> better at predicting mold related symptoms than culturable sampling.> The key here is the strength of the correlation. P < 0.01 or 0.05> are equivalent in scientific power. Neither prove one method is better> than the other.>> Some people make the assumption that because hyphae or other mold> fragments can produce

an allergic type reaction in a laboratory test,> that these products are a major source of the symptoms in people. The> fact is there is no data that show hyphae alone cause mold related> symptoms in people. It is extremely difficult to isolate hyphae from> the mold spores. It may be that you need 100 hyphae to produce the> same symptom as 1 mold spore. We simply do not know what exactly is> going on immunologically.>> This brings use back to QPCR. All analytic methods have a standard> analytical error. The SAE follows this rule. culturable<total> spore<<<< QPCR.>> The problem with QPCR is if you screw up, you are easily off by a> million. With the other analysis methods, you may be off by a factor> of 10.>> I have worked in the drug industry with PCR and these analytical and> production errors are NOT uncommon. Lots of stuff gets thrown

always> because of this.>> I have also seen QPCR results from clean, 1 year old wood, with no> visible mold growth, that the AIHA accredited lab reported levels of> 52,000,000. These same surfaces were negative on culturable methods.>> The thing that really bothers me with the EPA pushing QPCR, is that> they do not do culturable and total spore parallels in ALL of there> research.> Why not? EPA goes through all the trouble to get an expensive QPCR> research project funded, and then they don't use historical methods as> a reference to the research? Something is wrong here.>>> Until I see a broad based study comparing QPCR with culturable and> total spore sampling that shows a better predictions of mold related> symptoms, I will continue use culturable and total spore methods.>> Based on the existing science, I see no scientific justification

for> the extreme cost of QPCR analysis, except in very unusual circumstances> and then only along with culturable and total spore sampling.>> Bob B>>>>>>>>>>>

Everyone is raving about the all-new Yahoo! Mail beta.

November 26, 2006

,

I reviewed the TOC from the latest Fungal Research Group conference. I

could find no reference to QPCR.

Can you point me to the specific lecture?

Bob

November 26, 2006

Bob:

Thanks for the info on PCR. It provided some insight and answers to some of my questions and suspicions of PCR. Yes...Comparative results are warranted. Moreover, the cost of PCR/QPCR tends to make one collect, and rely on, fewer samples; and this is VERY risky when assessing biologicals. Appreciate the input.

--

Geyer, PE, CIH, CSP

President

KERNTEC Industries, Inc.

Bakersfield, California

www.kerntecindustries.com

,

" As many of you may know, several recent scientific studies have looked at species analysis from culture testing and found that they are pretty much random when compared to DNA profiling of the samples (called Quantitative PCR). Therefore culture testing for speciation is of no value. "

Can you provide references for this statement? Since QPCR only analyzes for some 30+ species, I have difficulty with this statement. Further, culturable methods used in microbiological diagnosis of mold infections in people have proven to be more than adequate from many years. This QPCR claim is in direct conflict with medical research methods.

Further, at this point in time, there is no published scientific evidence showing that QPCR has a stronger (higher correlation coefficient) to mold related symptoms or disease, than any of the other test methods.

The published research history showing a relationship between dampness, mold and respiratory symptoms was well established in many studies in the EU, almost 10 years ago. These studies were recently duplicated in the US. However, this was not new information.

There have also been studies in Germany and Canada that correlated culturable levels with symptoms. Most other studies relate also culturable levels to symptoms. This is why all of the mold exposure standards in other countries are set in culturable levels.

The only guideline on total spore concentrations is the AAAAI table. However, note that this table drastically changed in 1992, when AAAAI switch to Burhard from the Rot o Rod samplers.

There is also no study that has proven that total spore sampling is any better at predicting mold related symptoms than culturable sampling. The key here is the strength of the correlation. P < 0.01 or 0.05 are equivalent in scientific power. Neither prove one method is better than the other.

Some people make the assumption that because hyphae or other mold fragments can produce an allergic type reaction in a laboratory test, that these products are a major source of the symptoms in people. The fact is there is no data that show hyphae alone cause mold related symptoms in people. It is extremely difficult to isolate hyphae from the mold spores. It may be that you need 100 hyphae to produce the same symptom as 1 mold spore. We simply do not know what exactly is going on immunologically.

This brings use back to QPCR. All analytic methods have a standard analytical error. The SAE follows this rule. culturable<total spore<<<< QPCR.

The problem with QPCR is if you screw up, you are easily off by a million. With the other analysis methods, you may be off by a factor of 10.

I have worked in the drug industry with PCR and these analytical and production errors are NOT uncommon. Lots of stuff gets thrown always because of this.

I have also seen QPCR results from clean, 1 year old wood, with no visible mold growth, that the AIHA accredited lab reported levels of 52,000,000. These same surfaces were negative on culturable methods.

The thing that really bothers me with the EPA pushing QPCR, is that they do not do culturable and total spore parallels in ALL of there research.

Why not? EPA goes through all the trouble to get an expensive QPCR research project funded, and then they don't use historical methods as a reference to the research? Something is wrong here.

Until I see a broad based study comparing QPCR with culturable and total spore sampling that shows a better predictions of mold related symptoms, I will continue use culturable and total spore methods.

Based on the existing science, I see no scientific justification for the extreme cost of QPCR analysis, except in very unusual circumstances and then only along with culturable and total spore sampling.

Bob B

November 26, 2006

Based on my years of QA/QC experiences in mold labs, the following are some “general” facts of IAQ fungal analysis in quality laboratories (AIHA EMLAP accredited or not) that I can come up with. They do not including exceptions, and it’s assumed there is no error during analysis. If you have specific questions or different opinions on certain facts, I will try my best to explain why I think that way. (1) What do those methods analyze? EPA QPCR: fungal DNA (from viable cells, non-viable cells, cell fragments, biomass, etc.) Direct exam (spore traps/tape-lift): total fungi (viable cells and non-viable cells) Viable method: viable cells (culturable and non-culturable) Culture method: culturable cells (2) What method do they use? EPA QPCR: DNA polymerization chain reaction, which amplifies DNA molecule to measurable amount Direct exam (spore traps/tape-lift): microscopic direct examination Viable method: differential staining based on metabolic activity or cell structure integrity, or cell growth/germination Culture method: culturing on selected media to form colonies (3) What do they see? EPA QPCR: fluorescence signals detected by sensors Direct exam (spore traps/tape-lift): microscopic spores/hyphae (2 to 30 microns) Viable method: microscopic viable spores/hyphae or micro-colonies (2 to 100 microns) Culture method: visible colonies (3 mm to 10 cm) (4) Analysis time Direct exam (spore traps/tape-lift): 10 - 30 min EPA QPCR: 3 hr Viable method: 4 - 24 hr Culture method: 5 - 7 days (5) Cost per sample (reasonable TAT) Direct exam (spore traps/tape-lift): $25 - $40 Viable method: $40 - $50 Culture method: $30 - $50 EPA QPCR: $200 - $350 (6) Accuracy and

Precision --Accuracy of identification (from highest to lowest) (a) Culture method (gold standard) ( EPA QPCR (only when probe is available) © Direct exam (spore traps/tape-lift) = Viable method (d) EPA QPCR, when cross-reacted with

a different species ***Tape-lift analysis is not quantitative, therefore, it’s not included in the following comparisons. --Accuracy (to each own references) of enumeration (from highest to lowest) (a) Culture method = Viable method = EPA QPCR ( Direct exam of spore traps (huge difference between labs/analysts) © Culture method, when overgrowth or competition between different species occurs (d) EPA QPCR, when reaction is inhibited by unwanted substance (e.g. gypsum dust) ***When concentrations of different species are greater than 100 times difference, EPA QPCR is best in enumeration of the small amount species. However, it’s usually not necessary to know those species (<1% of total).

--Precision of enumeration (from best to worst) (a) Culture method = Viable method = EPA QPCR ( Direct exam of spore traps (huge variations between labs/analysts) Wei Tang QLab Wei Tang, Ph.D.Lab Director QLab5 DriveCherry Hill, NJ 08003www.QLabUSA.com

November 27, 2006

, You wrote: "Aerotech has a new PCR procedure where you take a dust sample and submit it for PCR analysis and they cross it to an EPA data base on mold species found in sick homes and the results give you a sick house index." ERMI is developed by EPA (not Aerotech) and it's available in those licensed labopratories who believe it's useful. Anyone who can turn on a swith and vacuum a carpet can pretty much do the sampling. That inlcudes totally inexperienced inspectors and even home owners. But, don't worry yet, I think this technology still need more research and more willing customers for the high cost. And, it still doesn't tell you where the mold is (hidden or not). Therefore, after spending hundreds of dollars, you still need to look for mold and the area that has water-problem. Wei Tang QLab EPA http://www.epa.gov/microbes/moldtech.htm Aerotech http://www.aerotechpk.com/AnalyticalServices/ERMI.aspx EMSL http://www.emsl.com/index.cfm?nav=News & action=show & NewsID=213 gary rosen wrote: Re: Re: Is QPCR Better Bob My comments are in BOLD ,"As many of you may know, several recent scientific studies have looked at species analysis from culture testing and found that they are pretty much random when compared to DNA profiling of the samples (called Quantitative PCR). Therefore culture testing for speciation is of no

value."Can you provide references for this statement? Since QPCR only analyzes for some 30+ species, I have difficulty with this statement. Further, culturable methods used in microbiological diagnosis of mold infections in people have proven to be more than adequate from many years. This QPCR claim is in direct conflict with medical research methods. There are several articles in the latest edition of the research presented at last Fungal Research Group symposium. www.fungalresearchgroup.com. I recommend that everyone purchase a copy and review the entire conference proceedings. They represent the state of the art in our field. Further, at this point in time, there is no published scientific evidence showing

that QPCR has a stronger (higher correlation coefficient) to mold related symptoms or disease, than any of the other test methods. All I said was that culturable methods are not reliable in providing an accurate profile of mold species and genus based on the lastest published research.The published research history showing a relationship between dampness, mold and respiratory symptoms was well established in many studies in the EU, almost 10 years ago. These studies were recently duplicated in the US. However, this was not new information.There have also been studies in Germany and Canada that correlated culturable levels with symptoms. Most other studies relate also culturable levels to symptoms. This is why all of the mold exposure standards in other countries are set in culturable levels. There is

a diffence between correlation and reliable. Mold exposure levels are set using culturable levels in other countries because the US EPA developed the DNA profiling and the US is way ahead of Europe in that area. Although if you get the FRG book you will see that PCR is being use throughout the world. There is also no study that has proven that total spore sampling is any better at predicting mold related symptoms than culturable sampling. The key here is the strength of the correlation. P < 0.01 or 0.05 are equivalent in scientific power. Neither prove one method is better than the other. No doubt. We were talking about the value of culturable to get an accurate picture of the quantities of different species. It does not give you that.Some people make the assumption that because hyphae or other mold fragments can

produce an allergic type reaction in a laboratory test, that these products are a major source of the symptoms in people. The fact is there is no data that show hyphae alone cause mold related symptoms in people. Not true. Send me your email and I will give you a few articles to the contrary. It is extremely difficult to isolate hyphae from the mold spores. That's true. It may be that you need 100 hyphae to produce the same symptom as 1 mold spore. We simply do not know what exactly is going on immunologically. That's true.This brings use back to QPCR. All analytic methods have a standard analytical error. The SAE follows this rule. culturable<total spore<<<<

QPCR.The problem with QPCR is if you screw up, you are easily off by a million. With the other analysis methods, you may be off by a factor of 10. If you screw up nothing is good. That's why you take duplicates or triplicates when something is important.I have worked in the drug industry with PCR and these analytical and production errors are NOT uncommon. Lots of stuff gets thrown always because of this.I have also seen QPCR results from clean, 1 year old wood, with no visible mold growth, that the AIHA accredited lab reported levels of 52,000,000. These same surfaces were negative on culturable methods. That's because the mold was DEAD. PCR does not care if alive or dead. ***Dead mold also causes health problems so we want to know total when clearing a

contaminated location***. The thing that really bothers me with the EPA pushing QPCR, is that they do not do culturable and total spore parallels in ALL of there research. If you check out my book "Your Guide to Mold Toxins" on Amazon.com you will get a number of references about the EPA research. They don't use historical (culturable) methods for speciation because they don't work. And total spore count does not give you speciation. Why not? EPA goes through all the trouble to get an expensive QPCR research project funded, and then they don't use historical methods as a reference to the research? Something is wrong here. Not really. That's just progress. They are providing excellent tools. Aerotech has a new PCR procedure where you take a dust sample and submit it for PCR

analysis and they cross it to an EPA data base on mold species found in sick homes and the results give you a sick house index. That is very powerful stuff.Until I see a broad based study comparing QPCR with culturable and total spore sampling that shows a better predictions of mold related symptoms, I will continue use culturable and total spore methods. Based on the existing science, I see no scientific justification for the extreme cost of QPCR analysis, except in very unusual circumstances and then only along with culturable and total spore sampling. I use spore counts 99% of the time. QPCR is only used when it needs to be used due to cost. Rarely do I care about speciation. That's where the threat started.... But I think you might want to review the research on the value of the culturable for ANY quantitative or qualitative results.Bob B , <bold><smaller><smaller>"As many of you may know, several recentscientific studies have looked at species analysis from culturetesting and found that they are pretty much random when compared toDNA profiling of the samples (called Quantitative PCR). Thereforeculture testing for speciation is of no value."</smaller></smaller></bold><smaller><smaller>Can you providereferences for this statement? Since QPCR only analyzes for some 30+species, I have difficulty with this statement. Further, culturablemethods used in microbiological diagnosis of mold infections in peoplehave proven to be more than adequate from many years. This QPCR claimis in direct conflict with medical research methods. Further, at this point in time, there is no published scientificevidence showing that QPCR has a stronger (higher

correlationcoefficient) to mold related symptoms or disease, than any of theother test methods. The published research history showing a relationship between dampness, mold and respiratory symptoms was well established in manystudies in the EU, almost 10 years ago. These studies were recentlyduplicated in the US. However, this was not new information. There have also been studies in Germany and Canada that correlatedculturable levels with symptoms. Most other studies relate alsoculturable levels to symptoms. This is why all of the mold exposurestandards in other countries are set in culturable levels. The only guideline on total spore concentrations is the AAAAI table. However, note that this table drastically changed in 1992, when AAAAIswitch to Burhard from the Rot o Rod samplers. There is also no study that has proven that total

spore sampling isany better at predicting mold related symptoms than culturablesampling. The key here is the strength of the correlation. P <<0.01 or 0.05 are equivalent in scientific power. Neither prove onemethod is better than the other. Some people make the assumption that because hyphae or other moldfragments can produce an allergic type reaction in a laboratory test,that these products are a major source of the symptoms in people. The fact is there is no data that show hyphae alone cause mold relatedsymptoms in people. It is extremely difficult to isolate hyphae fromthe mold spores. It may be that you need 100 hyphae to produce thesame symptom as 1 mold spore. We simply do not know what exactly isgoing on immunologically. This brings use back to QPCR. All analytic methods have a

standardanalytical error. The SAE follows this rule. culturable<<totalspore<<<<<<<< QPCR.The problem with QPCR is if you screw up, you are easily off by amillion. With the other analysis methods, you may be off by a factorof 10. I have worked in the drug industry with PCR and these analytical andproduction errors are NOT uncommon. Lots of stuff gets thrown alwaysbecause of this. I have also seen QPCR results from clean, 1 year old wood, with novisible mold growth, that the AIHA accredited lab reported levels of52,000,000. These same surfaces were negative on culturable methods. The thing that really bothers me with the EPA pushing QPCR, is thatthey do not do culturable and total spore parallels in ALL of thereresearch. Why not? EPA goes through all the trouble

to get an expensive QPCRresearch project funded, and then they don't use historical methods asa reference to the research? Something is wrong here. Until I see a broad based study comparing QPCR with culturable andtotal spore sampling that shows a better predictions of mold relatedsymptoms, I will continue use culturable and total spore methods. Based on the existing science, I see no scientific justification forthe extreme cost of QPCR analysis, except in very unusualcircumstances and then only along with culturable and total sporesampling.Bob B<bold></bold></smaller></smaller> Everyone is raving about the all-new Yahoo! Mail beta. Wei Tang, Ph.D.Lab Director QLab5

DriveCherry Hill, NJ 08003www.QLabUSA.com

November 27, 2006

Wei,

Nice review of the SAE of the methods.

Do you have a list of the 30 mold species that QPCR looks for?

If there are other species present, QPCR does not find them? (or does

some other DNA typing give a partial reading.)

Bob

November 27, 2006

Wei Tang,

Agreed. As far as I know the PCR technology in use by Aeorotech and other labs was all developed by the EPA.

This procedure does not tell you where the mold is. It does not take away our jobs. It is expensive. But it is very useful in a legal case to say that "based on new mold DNA profiling techniques, test results when crossed to an EPA provided data base show that the environment falls into the category of a "sick home".

I think that is powerful.

Rosen

Re: Re: Is QPCR Better

Bob

My comments are in BOLD

,"As many of you may know, several recent scientific studies have looked at species analysis from culture testing and found that they are pretty much random when compared to DNA profiling of the samples (called Quantitative PCR). Therefore culture testing for speciation is of no value."Can you provide references for this statement? Since QPCR only analyzes for some 30+ species, I have difficulty with this statement. Further, culturable methods used in microbiological diagnosis of mold infections in people have proven to be more than adequate from many years. This QPCR claim is in direct conflict with medical research methods.

There are several articles in the latest edition of the research presented at last Fungal Research Group symposium. www.fungalresearchg roup.com. I recommend that everyone purchase a copy and review the entire conference proceedings. They represent the state of the art in our field.

Further, at this point in time, there is no published scientific evidence showing that QPCR has a stronger (higher correlation coefficient) to mold related symptoms or disease, than any of the other test methods.

All I said was that culturable methods are not reliable in providing an accurate profile of mold species and genus based on the lastest published research.The published research history showing a relationship between dampness, mold and respiratory symptoms was well established in many studies in the EU, almost 10 years ago. These studies were recently duplicated in the US. However, this was not new information.There have also been studies in Germany and Canada that correlated culturable levels with symptoms. Most other studies relate also culturable levels to symptoms. This is why all of the mold exposure standards in other countries are set in culturable levels.

There is a diffence between correlation and reliable. Mold exposure levels are set using culturable levels in other countries because the US EPA developed the DNA profiling and the US is way ahead of Europe in that area. Although if you get the FRG book you will see that PCR is being use throughout the world.

There is also no study that has proven that total spore sampling is any better at predicting mold related symptoms than culturable sampling. The key here is the strength of the correlation. P < 0.01 or 0.05 are equivalent in scientific power. Neither prove one method is better than the other.

No doubt. We were talking about the value of culturable to get an accurate picture of the quantities of different species. It does not give you that.Some people make the assumption that because hyphae or other mold fragments can produce an allergic type reaction in a laboratory test, that these products are a major source of the symptoms in people. The fact is there is no data that show hyphae alone cause mold related symptoms in people.

Not true. Send me your email and I will give you a few articles to the contrary.

It is extremely difficult to isolate hyphae from the mold spores.

That's true.

It may be that you need 100 hyphae to produce the same symptom as 1 mold spore. We simply do not know what exactly is going on immunologically.

That's true.This brings use back to QPCR. All analytic methods have a standard analytical error. The SAE follows this rule. culturable<total spore<<<< QPCR.The problem with QPCR is if you screw up, you are easily off by a million. With the other analysis methods, you may be off by a factor of 10.

If you screw up nothing is good. That's why you take duplicates or triplicates when something is important.I have worked in the drug industry with PCR and these analytical and production errors are NOT uncommon. Lots of stuff gets thrown always because of this.I have also seen QPCR results from clean, 1 year old wood, with no visible mold growth, that the AIHA accredited lab reported levels of 52,000,000. These same surfaces were negative on culturable methods.

That's because the mold was DEAD. PCR does not care if alive or dead.

***Dead mold also causes health problems so we want to know total when clearing a contaminated location***.

The thing that really bothers me with the EPA pushing QPCR, is that they do not do culturable and total spore parallels in ALL of there research.

If you check out my book "Your Guide to Mold Toxins" on Amazon.com you will get a number of references about the EPA research. They don't use historical (culturable) methods for speciation because they don't work. And total spore count does not give you speciation.

Why not? EPA goes through all the trouble to get an expensive QPCR research project funded, and then they don't use historical methods as a reference to the research? Something is wrong here.

Not really. That's just progress. They are providing excellent tools. Aerotech has a new PCR procedure where you take a dust sample and submit it for PCR analysis and they cross it to an EPA data base on mold species found in sick homes and the results give you a sick house index. That is very powerful stuff.Until I see a broad based study comparing QPCR with culturable and total spore sampling that shows a better predictions of mold related symptoms, I will continue use culturable and total spore methods.

Based on the existing science, I see no scientific justification for the extreme cost of QPCR analysis, except in very unusual circumstances and then only along with culturable and total spore sampling.

I use spore counts 99% of the time. QPCR is only used when it needs to be used due to cost. Rarely do I care about speciation. That's where the threat started.... But I think you might want to review the research on the value of the culturable for ANY quantitative or qualitative results.Bob B

, <bold><smaller><smaller>"As many of you may know, several recentscientific studies have looked at species analysis from culturetesting and found that they are pretty much random when compared toDNA profiling of the samples (called Quantitative PCR). Thereforeculture testing for speciation is of no value."</smaller></smaller></bold><smaller><smaller>Can you providereferences for this statement? Since QPCR only analyzes for some 30+species, I have difficulty with this statement. Further, culturablemethods used in microbiological diagnosis of mold infections in peoplehave proven to be more than adequate from many years. This QPCR claimis in direct conflict with medical research methods. Further, at this point in time, there is no published scientificevidence showing that QPCR has a stronger (higher

correlationcoefficient) to mold related symptoms or disease, than any of theother test methods. The published research history showing a relationship between dampness, mold and respiratory symptoms was well established in manystudies in the EU, almost 10 years ago. These studies were recentlyduplicated in the US. However, this was not new information. There have also been studies in Germany and Canada that correlatedculturable levels with symptoms. Most other studies relate alsoculturable levels to symptoms. This is why all of the mold exposurestandards in other countries are set in culturable levels. The only guideline on total spore concentrations is the AAAAI table. However, note that this table drastically changed in 1992, when AAAAIswitch to Burhard from the Rot o Rod samplers. There is also no study that has proven that total

spore sampling isany better at predicting mold related symptoms than culturablesampling. The key here is the strength of the correlation. P <<0.01 or 0.05 are equivalent in scientific power. Neither prove onemethod is better than the other. Some people make the assumption that because hyphae or other moldfragments can produce an allergic type reaction in a laboratory test,that these products are a major source of the symptoms in people. The fact is there is no data that show hyphae alone cause mold relatedsymptoms in people. It is extremely difficult to isolate hyphae fromthe mold spores. It may be that you need 100 hyphae to produce thesame symptom as 1 mold spore. We simply do not know what exactly isgoing on immunologically. This brings use back to QPCR. All analytic methods have a

standardanalytical error. The SAE follows this rule. culturable<<totalspore<<<<<<<< QPCR.The problem with QPCR is if you screw up, you are easily off by amillion. With the other analysis methods, you may be off by a factorof 10. I have worked in the drug industry with PCR and these analytical andproduction errors are NOT uncommon. Lots of stuff gets thrown alwaysbecause of this. I have also seen QPCR results from clean, 1 year old wood, with novisible mold growth, that the AIHA accredited lab reported levels of52,000,000. These same surfaces were negative on culturable methods. The thing that really bothers me with the EPA pushing QPCR, is thatthey do not do culturable and total spore parallels in ALL of thereresearch. Why not? EPA goes through all the trouble

to get an expensive QPCRresearch project funded, and then they don't use historical methods asa reference to the research? Something is wrong here. Until I see a broad based study comparing QPCR with culturable andtotal spore sampling that shows a better predictions of mold relatedsymptoms, I will continue use culturable and total spore methods. Based on the existing science, I see no scientific justification forthe extreme cost of QPCR analysis, except in very unusualcircumstances and then only along with culturable and total sporesampling.Bob B<bold></bold></smaller></smaller>

Everyone is raving about the all-new Yahoo! Mail beta.

Wei Tang, Ph.D.Lab Director

QLab5 DriveCherry Hill, NJ 08003www.QLabUSA. com

Everyone is raving about the all-new Yahoo! Mail beta.

November 27, 2006

Bob, If you don't select (and pay for) the probe/primers for a specific species (group), you don't see them at all. However, they do have universal probe/primers for "Penicillium, Aspergillus and Paecilomyces varioti". The whole list is here. http://www.epa.gov/microbes/moldtech.htm Universal primers (public) for fungi is available for PCR (not part of EPA's patent). I am not sure if there is one avbailable for QPCR. Anyone here can answer that? List of ERMI fungi: http://www.emsl. com/index. cfm?nav=News & actionfiltered=show & NewsID=213 http://www.aerotech pk.com/Analytica lServices/ ERMI.aspx Wei Tang QLab Bob s wrote: Wei,Nice review of the SAE of the methods.Do you have a list of the 30 mold species that QPCR looks for?If there are other species present, QPCR does not find them? (or does some other DNA typing give a partial

reading.)Bob Wei Tang, Ph.D.Lab Director QLab5 DriveCherry Hill, NJ

08003www.QLabUSA.com

November 27, 2006

In Ch 7 Articles on pages 327 and 335 have QPCR in their titles. The later is written by Chin Yang. There are other articles in this volume that discuss QPCR as I recall but they don't have QPCR in their titles.

Make sure you are looking at the 2005 edition and not earlier editions.

Re: Re: Is QPCR Better

,I reviewed the TOC from the latest Fungal Research Group conference. I could find no reference to QPCR.Can you point me to the specific lecture?Bob

__________________________________________________

November 27, 2006

,

Your last statement hits at the heart of the problem. You wrote:

" ...show that the environment falls into the category of a " sick

home " . "

How does this or any other procedure determine a " sick home? "

Carl Grimes

Healthy Habitats LLC

-----

>

> Wei Tang,

>

> Agreed. As far as I know the PCR technology in use by Aeorotech and

> other labs was all developed by the EPA.

>

> This procedure does not tell you where the mold is. It does not take

> away our jobs. It is expensive. But it is very useful in alegal

> case to say that " based on new mold DNA profiling techniques, test

> results when crossed to an EPA provided data base show that the

> environment falls into the category of a " sick home " .

>

> I think that is powerful.

>

> Rosen

>

> Re: Re: Is QPCR Better

>

> Bob

>

> My comments are in BOLD

>

> ,

>

> " As many of you may know, several recent scientific studies have

> looked

> at species analysis from culture testing and found that they are

> pretty

> much random when compared to DNA profiling of the samples (called

> Quantitative PCR). Therefore culture testing for speciation is of no

> value. "

>

> Can you provide references for this statement?Since QPCR only

> analyzes for some 30+ species, I have difficulty with this statement.

> Further, culturable methods used in microbiological diagnosis of mold

> infections in people have proven to be more than adequate from many

> years.This QPCR claim is in direct conflict with medical research

> methods.

> There are several articles in the latest edition of the research

> presented at last Fungal Research Group

> symposium.www.fungalresearchg roup.com. I recommend that everyone

> purchase a copy and review the entire conference proceedings. They

> represent the state of the art in our field.

>

> Further, at this point in time, there is no published scientific

> evidence showing that QPCR has a stronger (higher correlation

> coefficient) to mold related symptoms or disease, than any of the

> other

> test methods.

>

> All I said was that culturable methods are not reliable in providing

> an accurate profile of mold species and genus based on the lastest

> published research.

>

> The published research history showing a relationship between

> dampness, mold and respiratory symptoms was well established in many

> studies in the EU, almost 10 years ago.These studies were recently

> duplicated in the US.However, this was not new information.

>

> There have also been studies in Germany and Canada that correlated

> culturable levels with symptoms. Most other studies relate also

> culturable levels to symptoms.This is why all of the mold exposure

> standards in other countries are set in culturable levels.

> There is a diffence between correlation and reliable. Mold exposure

> levels are set using culturable levels in other countries because the

> US EPA developed the DNA profiling and the US is way ahead of Europe

> in that area. Although if you get the FRG book you will see that PCR

> is being use throughout the world.

> There is also no study that has proven that total spore sampling is

> any

> better at predicting mold related symptoms than culturable sampling.

> The key here is the strength of the correlation. P < 0.01 or 0.05

> are equivalent in scientific power.Neither prove one method is

> better

> than the other.

> No doubt. We were talking about the value of culturable to get an

> accurate picture of the quantities of different species. It does not

> give you that.

> Some people make the assumption that because hyphae or other mold

> fragments can produce an allergic type reaction in a laboratory test,

> that these products are a major source of the symptoms in people.

> The

> fact is there is no data that show hyphae alone cause mold related

> symptoms in people.

>

> Not true. Send me your email and I will give you a few articles to

> the contrary.

>

> It is extremely difficult to isolate hyphae from

> the mold spores.

>

> That's true.

> It may be that you need 100 hyphae to produce the

> same symptom as 1 mold spore.We simply do not know what exactly is

> going on immunologically.

> That's true.

> This brings use back to QPCR. All analytic methods have a standard

> analytical error.The SAE follows this rule.culturable<total

> spore<<<< QPCR.

>

> The problem with QPCR is if you screw up, you are easily off by a

> million.With the other analysis methods, you may be off by a factor

> of 10.

> If you screw up nothing is good. That's why you take duplicates or

> triplicates when something is important.

> I have worked in the drug industry with PCR and these analytical and

> production errors are NOT uncommon.Lots of stuff gets thrown always

> because of this.

>

> I have also seen QPCR results from clean, 1 year old wood, with no

> visible mold growth, that the AIHA accredited lab reported levels of

> 52,000,000. These same surfaces were negative on culturable

> methods.

> That's because the mold was DEAD. PCR does not care if alive or

> dead.

>

> ***Dead mold also causes health problems so we want to know total

> when clearing a contaminated location***.

>

> The thing that really bothers me with the EPA pushing QPCR, is that

> they do not do culturable and total spore parallels in ALL of there

> research.

> If you check out my book " Your Guide to Mold Toxins " on Amazon.com

> you will get a number of references about the EPA research. They

> don't use historical (culturable) methods for speciation because they

> don't work. And total spore count does not give you speciation.

>

> Why not? EPA goes through all the trouble to get an expensive QPCR

> research project funded, and then they don't use historical methods

> as

> a reference to the research? Something is wrong here.

> Not really. That's just progress. They are providing excellent

> tools. Aerotech has a new PCR procedure where you take a dust sample

> and submit it for PCR analysis and they cross it to an EPA data base

> on mold species found in sick homes and the results give you a sick

> house index. That is very powerful stuff.

>

> Until I see a broad based study comparing QPCR with culturable and

> total spore sampling that shows a better predictions of mold related

> symptoms, I will continue use culturable and total spore methods.

> Based on the existing science, I see no scientific justification for

> the extreme cost of QPCR analysis, except in very unusual

> circumstances

> and then only along with culturable and total spore sampling.

> I use spore counts 99% of the time. QPCR is only used when it needs

> to be used due to cost. Rarely do I care about speciation. That's

> where the threat started.... But I think you might want to review

> the research on the value of the culturable for ANY quantitative or

> qualitative results.

>

> Bob B

> ,

>

> <bold><smaller><smaller> " As many of you may know, several recent

> scientific studies have looked at species analysis from culture

> testing and found that they are pretty much random when compared to

> DNA profiling of the samples (called Quantitative PCR). Therefore

> culture testing for speciation is of no value. "

>

> </smaller></smaller></bold><smaller><smaller>Can you provide

> references for this statement?Since QPCR only analyzes for some 30+

> species, I have difficulty with this statement. Further, culturable

> methods used in microbiological diagnosis of mold infections in people

> have proven to be more than adequate from many years.This QPCR claim

> is in direct conflict with medical research methods.

>

> Further, at this point in time, there is no published scientific

> evidence showing that QPCR has a stronger (higher correlation

> coefficient) to mold related symptoms or disease, than any of the

> other test methods.

>

> The published research history showing a relationship between

> dampness, mold and respiratory symptoms was well established in many

> studies in the EU, almost 10 years ago.These studies were recently

> duplicated in the US.However, this was not new information.

>

> There have also been studies in Germany and Canada that correlated

> culturable levels with symptoms. Most other studies relate also

> culturable levels to symptoms.This is why all of the mold exposure

> standards in other countries are set in culturable levels.

>

> The only guideline on total spore concentrations is the AAAAI table.

> However, note that this table drastically changed in 1992, when AAAAI

> switch to Burhard from the Rot o Rod samplers.

>

> There is also no study that has proven that total spore sampling is

> any better at predicting mold related symptoms than culturable

> sampling.The key here is the strength of the correlation. P <<

> 0.01 or 0.05are equivalent in scientific power.Neither prove one

> method is better than the other.

>

> Some people make the assumption that because hyphae or other mold

> fragments can produce an allergic type reaction in a laboratory test,

> that these products are a major source of the symptoms in people.

> The fact is there is no data that show hyphae alone cause mold related

> symptoms in people.It is extremely difficult to isolate hyphae from

> the mold spores. It may be that you need 100 hyphae to produce the

> same symptom as 1 mold spore.We simply do not know what exactly is

> going on immunologically.

>

> This brings use back to QPCR. All analytic methods have a standard

> analytical error.The SAE follows this rule.culturable<<total

> spore<<<<<<<< QPCR.

>

> The problem with QPCR is if you screw up, you are easily off by a

> million.With the other analysis methods, you may be off by a factor

> of 10.

>

> I have worked in the drug industry with PCR and these analytical and

> production errors are NOT uncommon.Lots of stuff gets thrown always

> because of this.

>

> I have also seen QPCR results from clean, 1 year old wood, with no

> visible mold growth, that the AIHA accredited lab reported levels of

> 52,000,000. These same surfaces were negative on culturable

> methods.

>

> The thing that really bothers me with the EPA pushing QPCR, is that

> they do not do culturable and total spore parallels in ALL of there

> research.

>

> Why not? EPA goes through all the trouble to get an expensive QPCR

> research project funded, and then they don't use historical methods as

> a reference to the research? Something is wrong here.

>

> Until I see a broad based study comparing QPCR with culturable and

> total spore sampling that shows a better predictions of mold related

> symptoms, I will continue use culturable and total spore methods.

>

> Based on the existing science, I see no scientific justification for

> the extreme cost of QPCR analysis, except in very unusual

> circumstances and then only along with culturable and total spore

> sampling.

>

> Bob B<bold>

>

> </bold></smaller></smaller>

>

> Everyone is raving about the all-new Yahoo! Mail beta.

>

> Wei Tang, Ph.D.

> Lab Director

> QLab

> 5 Drive

> Cherry Hill, NJ 08003

>

> www.QLabUSA. com

>

> Everyone is raving about the all-new Yahoo! Mail beta.

>

November 27, 2006

Carl,

Please go to the Aerotech P & K web site that describes the ERMI technology. I am sure other companies may offer similar programs but I am familiar with the Aerotech offerings. Because QPCR needs plenty of material, you collect carpet dust using (an IESO approved) carpet dust collection technique. I would assume that you could also take air samples but the marketing release says dust.I have submitted air samples, dust samples, and bulk samples for QPCR. When you take air samples for QPCR you need to run the pump for several hours since you need plenty of material.

http://www.aerotechpk.com/AnalyticalServices/ERMI.aspx

ERMI©

The EPA Relative Moldiness Index

Welcome to the Aerotech P & K's offical ERMI website, the only place to find everything you need to know about the ERMI test and how to use it! What is ERMI?ERMI is the EPA Relative Moldiness Index – the combination of EPA research, powerful PCR technology, and a new method to screen homes for mold. Based on recently published data from EPA researchers and the 2006 HUD American Healthy Home Survey, the test has been developed as a tool to evaluate the potential risk of indoor mold growth and associated health effects. How does it work?The test involves the analysis of a single sample of dust from a home. The sample is analyzed using mold-specific quantitative polymerase chain reaction (MSQPCR), a highly specific DNA-based method for quantifying mold species. A simple algorithm is used to calculate a ratio of water damage-related species to common indoor molds and the

resulting score is called the EPA Relative Moldiness Index or ERMI©. The ERMI value is typically between -10 and 20. In order to most effectively use this new tool, the ERMI must be compared to a national database. Indices were determined using this method for 1,096 homes across the U.S. as part of the 2006 HUD American Healthy Home Survey. Individual indices, ranked from lowest to highest were used to create a national Relative Moldiness Index (RMI) Scale. How was it developed? In initial studies by the EPA, the concentrations of different mold species in “moldy homes” (homes with visible mold growth or a history of water damage) and “reference homes” (homes with no visible mold) were compared. Based on those results, mold species were selected and grouped into those with higher concentrations in moldy homes (group1) and those with lower concentrations (group2). For the calculation of the ERMI, all concentrations are log-transformed and

the sum of group 2 is subtracted from the sum of group 1. What are the advantages?In addition to the simplicity of taking only one sample, the ERMI offers several advantages over traditional mold screening methods. Carpet dust acts as a reservoir for mold spores and is more representative of mold levels over time versus short term air samples. The use of MSQPCR for this test allows for increased precision as it is based on a biochemical assay using calibrated instrumentation. Further research is being conducted and published that will link the ERMI assessing health risks for susceptible individuals. This information along with the national database will be invaluable in providing an objective and standardized method for screening homes for mold.

Re: Re: Is QPCR Better> > Bob> > My comments are in BOLD> > ,> > "As many of you may know, several recent scientific studies have > looked > at species analysis from culture testing and found that they are > pretty > much random when compared to DNA profiling of the samples (called > Quantitative PCR). Therefore culture testing for speciation is of no > value."> > Can you provide references for this statement?Since QPCR only > analyzes for some 30+ species, I have difficulty with this statement. > Further, culturable methods used in microbiological diagnosis of mold > infections in people have proven to be more than adequate from many > years.This QPCR claim is in direct conflict with medical research > methods.> There are several

articles in the latest edition of the research > presented at last Fungal Research Group > symposium.www. fungalresearchg roup.com. I recommend that everyone > purchase a copy and review the entire conference proceedings. They > represent the state of the art in our field.> > Further, at this point in time, there is no published scientific > evidence showing that QPCR has a stronger (higher correlation > coefficient) to mold related symptoms or disease, than any of the > other > test methods.> > All I said was that culturable methods are not reliable in providing > an accurate profile of mold species and genus based on the lastest > published research.> > The published research history showing a relationship between> dampness, mold and respiratory symptoms was well established in many > studies in the EU, almost 10 years ago.These studies were

recently > duplicated in the US.However, this was not new information.> > There have also been studies in Germany and Canada that correlated > culturable levels with symptoms. Most other studies relate also > culturable levels to symptoms.This is why all of the mold exposure > standards in other countries are set in culturable levels.> There is a diffence between correlation and reliable. Mold exposure > levels are set using culturable levels in other countries because the > US EPA developed the DNA profiling and the US is way ahead of Europe > in that area. Although if you get the FRG book you will see that PCR > is being use throughout the world.> There is also no study that has proven that total spore sampling is > any > better at predicting mold related symptoms than culturable sampling.> The key here is the strength of the correlation. P < 0.01 or 0.05>

are equivalent in scientific power.Neither prove one method is > better > than the other.> No doubt. We were talking about the value of culturable to get an > accurate picture of the quantities of different species. It does not > give you that.> Some people make the assumption that because hyphae or other mold > fragments can produce an allergic type reaction in a laboratory test, > that these products are a major source of the symptoms in people. > The > fact is there is no data that show hyphae alone cause mold related > symptoms in people.> > Not true. Send me your email and I will give you a few articles to > the contrary.> > It is extremely difficult to isolate hyphae from > the mold spores. > > That's true.> It may be that you need 100 hyphae to produce the > same symptom as 1 mold spore.We simply do not know what exactly

is > going on immunologically.> That's true.> This brings use back to QPCR. All analytic methods have a standard > analytical error.The SAE follows this rule.culturable< total > spore<<<< QPCR.> > The problem with QPCR is if you screw up, you are easily off by a > million.With the other analysis methods, you may be off by a factor > of 10.> If you screw up nothing is good. That's why you take duplicates or > triplicates when something is important.> I have worked in the drug industry with PCR and these analytical and > production errors are NOT uncommon.Lots of stuff gets thrown always > because of this.> > I have also seen QPCR results from clean, 1 year old wood, with no > visible mold growth, that the AIHA accredited lab reported levels of > 52,000,000. These same surfaces were negative on culturable > methods.>

That's because the mold was DEAD. PCR does not care if alive or > dead.> > ***Dead mold also causes health problems so we want to know total > when clearing a contaminated location***. > > The thing that really bothers me with the EPA pushing QPCR, is that > they do not do culturable and total spore parallels in ALL of there > research.> If you check out my book "Your Guide to Mold Toxins" on Amazon.com > you will get a number of references about the EPA research. They > don't use historical (culturable) methods for speciation because they > don't work. And total spore count does not give you speciation.> > Why not? EPA goes through all the trouble to get an expensive QPCR > research project funded, and then they don't use historical methods > as > a reference to the research? Something is wrong here.> Not really. That's just progress. They are

providing excellent > tools. Aerotech has a new PCR procedure where you take a dust sample > and submit it for PCR analysis and they cross it to an EPA data base > on mold species found in sick homes and the results give you a sick > house index. That is very powerful stuff.> > Until I see a broad based study comparing QPCR with culturable and > total spore sampling that shows a better predictions of mold related > symptoms, I will continue use culturable and total spore methods.> Based on the existing science, I see no scientific justification for > the extreme cost of QPCR analysis, except in very unusual > circumstances > and then only along with culturable and total spore sampling.> I use spore counts 99% of the time. QPCR is only used when it needs > to be used due to cost. Rarely do I care about speciation. That's > where the threat started.... But I think you

might want to review > the research on the value of the culturable for ANY quantitative or > qualitative results.> > Bob B> , > > > <bold><smaller> <smaller> "As many of you may know, several recent> scientific studies have looked at species analysis from culture> testing and found that they are pretty much random when compared to> DNA profiling of the samples (called Quantitative PCR). Therefore> culture testing for speciation is of no value."> > > </smaller></ smaller>< /bold><smaller> <smaller> Can you provide> references for this statement?Since QPCR only analyzes for some 30+> species, I have difficulty with this statement. Further, culturable> methods used in microbiological diagnosis of mold infections in people> have proven to be more than adequate from many years.This QPCR

claim> is in direct conflict with medical research methods. > > > Further, at this point in time, there is no published scientific> evidence showing that QPCR has a stronger (higher correlation> coefficient) to mold related symptoms or disease, than any of the> other test methods. > > > The published research history showing a relationship between > dampness, mold and respiratory symptoms was well established in many> studies in the EU, almost 10 years ago.These studies were recently> duplicated in the US.However, this was not new information. > > > There have also been studies in Germany and Canada that correlated> culturable levels with symptoms. Most other studies relate also> culturable levels to symptoms.This is why all of the mold exposure> standards in other countries are set in culturable levels. > > > The only

guideline on total spore concentrations is the AAAAI table.> However, note that this table drastically changed in 1992, when AAAAI> switch to Burhard from the Rot o Rod samplers. > > > There is also no study that has proven that total spore sampling is> any better at predicting mold related symptoms than culturable> sampling.The key here is the strength of the correlation. P <<> 0.01 or 0.05are equivalent in scientific power.Neither prove one> method is better than the other. > > > Some people make the assumption that because hyphae or other mold> fragments can produce an allergic type reaction in a laboratory test,> that these products are a major source of the symptoms in people.> The fact is there is no data that show hyphae alone cause mold related> symptoms in people.It is extremely difficult to isolate hyphae from> the mold spores. It may be

that you need 100 hyphae to produce the> same symptom as 1 mold spore.We simply do not know what exactly is> going on immunologically. > > > This brings use back to QPCR. All analytic methods have a standard> analytical error.The SAE follows this rule.culturable< <total> spore<<<<<<< < QPCR.> > > The problem with QPCR is if you screw up, you are easily off by a> million.With the other analysis methods, you may be off by a factor> of 10. > > > I have worked in the drug industry with PCR and these analytical and> production errors are NOT uncommon.Lots of stuff gets thrown always> because of this.> > > I have also seen QPCR results from clean, 1 year old wood, with no> visible mold growth, that the AIHA accredited lab reported levels of> 52,000,000. These same surfaces were negative on

culturable > methods. > > > The thing that really bothers me with the EPA pushing QPCR, is that> they do not do culturable and total spore parallels in ALL of there> research.> > Why not? EPA goes through all the trouble to get an expensive QPCR> research project funded, and then they don't use historical methods as> a reference to the research? Something is wrong here.> > > > Until I see a broad based study comparing QPCR with culturable and> total spore sampling that shows a better predictions of mold related> symptoms, I will continue use culturable and total spore methods. > > > Based on the existing science, I see no scientific justification for> the extreme cost of QPCR analysis, except in very unusual> circumstances and then only along with culturable and total spore> sampling.> > > Bob

B<bold>> > > > > > > > > > > </bold></smaller> </smaller>> > > > > > Everyone is raving about the all-new Yahoo! Mail beta. > > > > > > Wei Tang, Ph.D.> Lab Director> QLab> 5 Drive> Cherry Hill, NJ 08003> > www.QLabUSA. com> > > > > > > > Everyone is raving about the all-new Yahoo! Mail beta.> >

Check out the all-new Yahoo! Mail beta - Fire up a more powerful email and get things done faster.

November 28, 2006

QPCR does not necessarily need a lot of material, but since it does not overload, so you can usually take more. The labs will take a subsample when there is too much to be prepared and analyzed. How much sample you need depends on what kind of detection limit (DL) you want and how much sample is representative. Of course, you can't go any lower than the DL for the analysis itself. Do be careful that materials in dust may inhibit the PCR reaction. Wei Tang QLabgary rosen wrote: Carl, Please go to the Aerotech P & K web site that describes the ERMI technology. I am sure other companies may offer similar programs but I am familiar with the Aerotech offerings. Because QPCR needs plenty of material, you collect carpet dust using (an IESO approved) carpet dust collection technique. I would assume that you could also take air samples but the marketing release says dust.I have submitted air samples, dust samples, and bulk samples for QPCR. When you take air samples for QPCR you need to run the pump for several

hours since you need plenty of material. http://www.aerotechpk.com/AnalyticalServices/ERMI.aspx ERMI© The EPA Relative Moldiness Index Welcome to the Aerotech P & K's offical ERMI website, the only place to find everything you need to know about the ERMI test and how to use it! What is ERMI?ERMI is the EPA Relative Moldiness

Index – the combination of EPA research, powerful PCR technology, and a new method to screen homes for mold. Based on recently published data from EPA researchers and the 2006 HUD American Healthy Home Survey, the test has been developed as a tool to evaluate the potential risk of indoor mold growth and associated health effects. How does it work?The test involves the analysis of a single sample of dust from a home. The sample is analyzed using mold-specific quantitative polymerase chain reaction (MSQPCR), a highly specific DNA-based method for quantifying mold species. A simple algorithm is used to calculate a ratio of water damage-related species to common indoor molds and the resulting score is called the EPA Relative Moldiness Index or ERMI©. The ERMI value is typically between -10 and 20. In order to most effectively use this new tool, the ERMI must be compared to a national database. Indices were determined using this method for

1,096 homes across the U.S. as part of the 2006 HUD American Healthy Home Survey. Individual indices, ranked from lowest to highest were used to create a national Relative Moldiness Index (RMI) Scale. How was it developed? In initial studies by the EPA, the concentrations of different mold species in “moldy homes” (homes with visible mold growth or a history of water damage) and “reference homes” (homes with no visible mold) were compared. Based on those results, mold species were selected and grouped into those with higher concentrations in moldy homes (group1) and those with lower concentrations (group2). For the calculation of the ERMI, all concentrations are log-transformed and the sum of group 2 is subtracted from the sum of group 1. What are the advantages?In addition to the simplicity of taking only one sample, the ERMI offers several advantages over traditional mold screening methods. Carpet dust acts as a reservoir for mold

spores and is more representative of mold levels over time versus short term air samples. The use of MSQPCR for this test allows for increased precision as it is based on a biochemical assay using calibrated instrumentation. Further research is being conducted and published that will link the ERMI assessing health risks for susceptible individuals. This information along with the national database will be invaluable in providing an objective and standardized method for screening homes for mold. Re: Re: Is QPCR Better> > Bob> > My comments are in BOLD> > ,> > "As many of you may know, several recent scientific studies have > looked > at species analysis from culture testing and found that they are > pretty > much random when compared to DNA profiling of the samples (called > Quantitative PCR). Therefore culture testing for speciation is of no > value."> > Can you provide references for this statement?Since QPCR only > analyzes for some 30+ species, I have difficulty with this statement. > Further, culturable methods used in microbiological diagnosis of mold > infections in people have proven to be more than adequate from many > years.This QPCR claim is in direct conflict with medical research > methods.> There are several