Our Mold sampling methods
There are various ways we test mold for toxicity. The methods we use to test mold normally depends on each situation, the type of microbial growth observed, the location, what you (the Client) has approved us to do and the accessibility of the sample.
When we ship mold samples to an accredited laboratory for analysis, we will get your’ approval first, as lab fees & costs can exceed $60.00 per sample. You will receive a copy of all paid for, lab reports. Generally, during the phone consultation we will discuss your problem(s) and agree on the services to be performed prior to our arrival. If there are additional areas of concern, we will note that at the time of services or include them with your laboratory analysis report.
Mold Microbial Sample Data
Whenever we take any sample, we always record the type of sampling such as air, swab, tape, or bulk, and record the location that the sample was taken from. Usually digital photos are taken of the location being tested and included in your report (if a report is requested). This may become important later for remediation purposes. We will also a record of the relative humidity, wind speed, temperature(s), lab codes, volume, and cassette type used for the sample, when applicable.
Tape sampling
We use tape sampling as an method for evaluating visual microbial growth on surfaces. Clear cellophane tape is pressed onto the sample area to lift the spores and organic mold materials. The tape sample is then placed inside a sterile container such as a plastic laboratory bag and mailed to a lab for microscopic analysis.
Tape sampling preserves the structure of the sample (conidiophores & hyphae) which can be helpful in the identification of the varieties of mold.
Bulk sampling
We use bulk sampling as another good method of collecting samples for laboratory analysis. Bulk sampling involves collecting an actual physical sample of the microbial growth in question.
Bulk samples will be obtained (with your/the owner's permission only) by scraping sample material into a plastic bag. In more extreme cases, it may be necessary or beneficial to remove some of the material affected by microbial growth (with your or the owner's written approval only) and submit the sample to the lab for analysis.
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This may include a piece of fabric, a section of carpet, or building material. Since a mold inspection is meant to be non-destructive, we will obtain your’ written permission before any destructive sampling is performed. If you are not the owner of the building, it will be your responsibility to obtain the owner's permission for destructive testing prior to the inspection/testing. Sometimes this will involve scheduling an additional inspection/testing, until permission can be obtained. For this reason, bulk sampling is not always the method of choice for sample collection.
Swab sampling
We use swab samples to identify microbial growths not easily accessible for a proper tape sample (discussed above). Swab sampling involves wiping a sterile laboratory swab across the microbial growth in question.
Once the swab has come into contact with the sample, it is put into a sealed, sterile laboratory container for microscopic evaluation at the lab.
Swab samples can be examined in two ways:
Direct examination - The lab can lift particles from the swab using tape or other materials to make a direct particle examination similar to tape sampling (above).
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Culturing-the lab rolls the swab across the culture plate to culture the sample for identification.
Air sampling
We obtain air samples by using high volume, calibrated air pumps with calibrated rotameters and bio isolation filters to collect a measured volume of an air. An identical air sample is collected for use as a comparative test.
Particles in the air are collected inside a specially designed spore trap cassette that accumulates mold spores and other particles as air is pumped through the devices air path.
Air sampling is not always the most reliable method of detection because the air sample in the test environment may not reflect the house as a whole due to some environmental factors that we will address (link - below). To avoid potential conditions that could promote less accurate results, please visit here. By following these recommendations prior to testing, you will ensure accurate results.
Air sampling will be performed only with your (the client) consent. We may recommend taking a physical sample(s) of visible mold using swabs, tape or bulk methods if possible, to give additional support to the air samples, if needed.
Vacuum sampling
Although, probably the least effective way in determining elevated mold conditions, we sometimes use vacuum sampling as a type of an air sampling used to extract a mold sample from a fibrous material such as carpet. This involves connecting a special collection canister to a vacuum pump which draws particles onto a filter surface or into a special collection container. On very rare occasions this form of testing can be somewhat useful. As a better substitute, tape sampling (see above) is usually used to test fibrous surfaces in most cases.
Vacuum samples can sometimes be useful for collecting samples from soft material such as carpet, clothing, drapery, or furniture. More than likely, air sampling will pick up molds from these areas and is recommended over vacuum sampling. Many times we will use tape sampling as a substitute over vacuum sampling after consultations with our microbiologist.
Vacuum sampling is used to get a general idea of overall mold contamination in an limited environment but is not very useful to identify the specific species of mold since usually more than one species is collected per sample. Most of the newer DNA mold tests are based on vacuum sampling, to their detriment.
