DNA testing for toxic mold emerges

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http://www.cmmonline.com/News.asp?mode=4 & N_ID=30779

DNA testing for toxic mold emerges

By Preuss

PARK RIDGE, IL A new lab near Chicago's O'Hare

International Airport will offer DNA-based testing for

stachybotrys chartarum (toxic black mold) and other

mold varieties, becoming only the fifth license holder

for the test in the United States.

Other laboratories are considering implementation of

the test method, although experts say that DNA testing

is limited in obtaining a clear picture of indoor air

quality (IAQ) through quantitative sampling as

provided by culture methods.

The DNA test method, developed and licensed by the US

Environmental Protection Agency, eliminates some of

the uncertainty of " culture " methods, which depend on

growing viable (living) samples in the lab. The test

uses real time Polymerase Chain Reaction (PCR), the

same method used in DNA crime scene detection methods.

" The method of choice to date has been to either

observe or to attempt to grow cultures, " Lighthouse

Marketing VP Jeff Heilbrunn told CM e-News

Daily/CleanfaxOnline. " DNA allows samples to be

gathered and tested without the issue of growing and

keeping cultures alive. "

Lighthouse is accepting pre-arrangements for testing

set to begin May 15 with pricing to be announced.

An industry expert commented that DNA-based testing

might be useful in identifying toxic molds and,

because it is already part of the legal culture (court

acceptance of DNA tests), it may have a place in the

mold remediation industry.

However, microbiologist Dr. Dobranic of EMSL

Analytical, Inc., told CM e-News Daily/CleanfaxOnline,

DNA-based tests provide a limited picture of indoor

air quality (IAQ).

DNA presence not indicative of spore count, viability

" At recent conferences, we've learned that you can't

relate the DNA to the number of spores, " Dobranic

said. " There may be plenty of DNA available and

detected by the test, but that may simply signal the

presence of lingering hyphae (the filaments of fungal

body); that doesn't mean there is mold in the building

that is producing spores. "

Consider the possibility that the hyphae might remain

in a building months or years after " live " mold has

disappeared & #8212; and that simple cleaning might be

the real " remedy. "

Test forces you to make " blind " decisions

DNA test probes are limited & #8212; a lab might sell a

" package " of five, 10, up to 15 species & #8212; not

the 1,000 or more different organisms that a culture

test can identify and quantify.

" With DNA testing, you must specify what you're

looking for, " Dobranic said.

Culture-based testing and the legal " culture "

Dobranic, who works in the Houston microbiology office

of NJ-based EMSL, said his company is evaluating

offering a DNA test.

" DNA-based testing may be useful to lawyers, " he said.

" We must consider it as customers may come to demand

the service. However, we believe there will always be

a place for culture-based testing. "

Cost issues

At present, industry experts say DNA-based testing is

more costly than culture testing.

However, Lighthouse plans to introduce DNA testing at

about $200 ... slightly higher than culture-based lab

testing, but not exponentially so.

" A few bucks more isn't a big deal, compared to the

potential health costs, " Heilbrunn said.

Limiting testing to toxic varieties helps control

costs ... and keep issues manageable.

An advantage: Speed

One advantage to DNA testing is speed. Dobranic agreed

that DNA testing could be useful for identifying toxi

mold varieties. Since there is no need to grow a

culture, results can be obtained very quickly.

The big picture There is speculation that matters like

these may become increasingly relevant in the

restoration/remediation and related industries.

Heilbrunn commented, " Some feel that the issue of mold

might surpass the $20 billion legacy of litigation

left so far in the wake of asbestos issue. "

Concerned parties include remodelers; HVAC; janitorial

and cleaning services; real estate

agents/lawyers/buyers and sellers; home inspectors;

mortgage and financial institutions and insurers, in

addition to property owners and managers.

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