No Foolin' -- 'Lab on a Chip' Works!

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Published: 11 hours ago, 12:47 EST, April 06, 2007

No Foolin' -- 'Lab on a Chip' Works!

LOCAD-PTS, a handheld biological laboratory for space travel.

http://www.physorg.com/news95082478.html

" What a huge relief, " says Norman Wainwright of the River

Laboratories in ton, SC. " The whole technical team was

delighted that it worked so well. "

He's talking about a miniature biological laboratory just tested for

the first time onboard the International Space Station. Called LOCAD-

PTS (short for Lab-On-a-Chip Application Development–Portable Test

System), the mini-lab detects the presence of bacteria or fungi on

the surfaces of a spacecraft far more rapidly than standard methods

of culturing.

" The ability to monitor microorganisms would be especially important

on long space voyages, not only to check the health of astronauts

but also to monitor electronics and structural materials, which can

be corroded or otherwise damaged by certain fungi and bacteria, "

says Wainwright, the experiment's principal investigator. LOCAD-PTS

is designed so that " astronauts can do the analysis onboard with no

need to return samples to laboratories on Earth. "

The device was launched last December 9th on board the space shuttle

Discovery, and then stowed aboard ISS until its scheduled experiment

time—which happened to be Saturday night, March 31, Marshall Space

Flight Center time. (Remember that time!)

Astronaut Sunita " Suni " opened the instrument kit bag,

assembled LOCAD-PTS, and then took six readings. " The first two

readings were controls to show that the instrument was operating

correctly, " explains Jake Maule, LOCAD-PTS project scientist at the

Carnegie Institution of Washington. " First she swabbed her palm,

which she had first pressed to handrails and other often-handled

surfaces that should have had lots of bacteria—and indeed, we got a

strong positive reading, " he continues. " Then she sampled some

ultraclean water in the instrument that is used to moisten samples,

to check that the water was truly clean—and indeed, we got a great

negative reading. "

Next, chose a wall panel in ISS Node 1 to test using both

LOCAD-PTS and, for comparison, a standard culturing method.

For the standard method, she pressed a layer of solid gel growth

medium (rather like agar) to the panel for a few seconds, replaced

it securely in its packaging, and then set it aside to incubate for

a few days.

Then she took a dry swab, rather like a high-tech Q-tip, from LOCAD-

PTS and rubbed it on the panel next to the same area. Flushing

ultraclean water through the swab converted the sample to liquid

form, and a few drops were dispensed into the hand-held LOCAD-PTS

instrument.

" The cleaner the sample, the longer the analysis takes, " Wainwright

says. " Because this site was pretty clean, it took about 12 minutes,

but dirty samples can take as little as a couple of minutes. "

It was during the wait that must have noted the time.

Although it was 10:20 PM Central Daylight Time at Marshall in

Huntsville, Alabama, where all the LOCAD-PTS scientists were

anxiously watching television monitors, it was actually past

midnight on April 1, Greenwich Mean Time, the time zone used by ISS.

" Suni said, 'Ah, this last set of readings for LOCAD-PTS looks a bit

strange,' " Maule recalls. " After a pause of about five seconds, she

exclaimed, 'Happy April Fools' Day! The numbers are just fine!' "

" She definitely got me! " he laughs.

Over the next few months, LOCAD-PTS and standard culture methods

will be used to investigate different parts of ISS. " A second-

generation of LOCAD-PTS cartridges for the specific detection of

fungi are scheduled to launch to ISS on Space Shuttle STS-123, " says

T. Lyons, LOCAD-PTS project manager at Marshall, the NASA

center that has overseen the project since its inception and

supervised getting the equipment spaceflight-ready. " With each

generation of cartridges, we are getting more and more specific in

what we detect. Our ultimate aim is to provide the crew with a

selection of cartridges for the detection of a wide variety of

target compounds, biological and chemical both inside and outside

the spacecraft—something that would be especially important for long-

duration missions to the Moon or to Mars. "

" Right now, we're very happy with the first tests. "

Source: By Trudy E. Bell, Science@NASA