The High Country’s Solution to Environmental Health & Safety

Blue Ridge Industrial Hygiene, Inc.

What is PCR Sampling?

PCR sampling collects mold spores onto a special filter and uses a new technology patented by the U.S. Environmental Protection Agency to count and identify the spores.  and using a specialized vacuum pump.  It is used to count and identify spores in the air, in a wall cavity, or in porous materials such as carpeting.  Spores can only be identified in a general way, not to the specific species.

Advantages:

· Based on the most advanced science on genetics.

· Provides accurate fungal identification all the way to the species level.

· More accurate & reliable than spore counting method — can identify exact species, and neither number counted nor type of mold identified is subject to technician error.

· Allows many hours of sampling, which can provide a more accurate picture of mold in the building.

· Offers the advantages of both culturable (good fungal identification) and spore count (quick turnaround) methods.

· Highly sensitive — can detect low levels.

· Can be cost effective — more expensive per sample but when taking into consideration the advantage of sampling for many hours and a very large air volume, can be less expensive overall.

Disdvantages:

· Must pre-select species to look for; often not a good screening tool (can be used for screening for water damage).

· Does not distinguish between live (“viable”) and dead (“nonviable”) spores.

· Does not offer limited information about whether the mold is likely to be growing (“amplifying”) or dead.

· Sampling itself takes longer, although lab analysis usually faster than spore trap.

· Not all mold species can be identified using PCR yet.

· False positives and negatives are possible, though using a quality lab reduces the chances for this occurring.

Spore Trap Sampling vs

PCR Sampling

What is Spore Count Sampling?

Spore trap sampling is a way of collecting mold spores onto a special sticky filter (the “spore trap”) using a specialized vacuum pump.  It is used to count and identify spores in the air, in a wall cavity, or in porous materials such as carpeting.  Spores can only be identified in a general way, not to the specific species.

Advantages:

· Quick — samples take 15 to 30 minutes each.

· Good screening tool — identifies all molds present.

· Can identify general types of molds (“genera”) and some species.

· Can provide some information on the mold’s activity — is it actively growing, dead, etc?

· Can also count and identify other airborne allergens (dander, dust mite, etc).

Disadvantages:

· Results are only a “snapshot” of the moment; spore levels can vary greatly from hour to hour as molds sporulate depending on the light, humidity, temperature, etc of the moment.  Thus many samples can be needed to take accurate “picture” of the problem.

· Results are highly dependent on the skill of the lab technician & quality of lab.

· Does not distinguish between live (“viable”) and dead (“nonviable”) spores.

· Only provides general identify of molds, can identify only a few to the specific species level (though this is not usually necessary).

The High Country’s Solution to Environmental Health & Safety