By using the power of qualitative polymerase chain reaction (qPCR a type of DNA Mold Testing), our lab can analyze samples for any number of fungi ranging from broad tests, such as the total Penicillium/Aspergillus group, to the species level, like Aspergillus fumigatus. qPCR uses a fluorescent probe in conjunction with primers to identify a certain region of DNA in a target organism. High temperatures, just shy of boiling, are applied to pure DNA extracted from the sample, thus breaking apart the DNA (melting it). Once the heat is lowered, the DNA comes back together and is replicated by enzymes with the primers and probe attached. This replication leads to the probe releasing a fluorescent signal via a process of “hydrolysis”. One of the most common qPCR testing panels in the industry is the ERMI panel, but there are several different analyses and sample collection methods. The following article will help guide you through the process of DNA mold testing.
qPCR testing can be performed on several different types of sampling media. The most common sample types are dust, air, or bulk.
Dust samples primarily come from carpet and are collected with a vacuum dust collector or from dust reservoirs using a sterile swab. Dust reservoirs are areas where dust commonly accumulates in untouched areas. Examples of dust reservoirs are on top of or behind a TV, on top of a picture frame, on top of a bed frame, etc. When using a swab, be careful not to collect from active growth or from areas with a high level of moisture (window sill, near a sink, etc. ). This can artificially inflate your results due to the sensitivity of the analysis. Analyzing mold through dust is a very common method for inspectors and homeowners to assess the moldiness of a facility. Essentially, analyzing dust in a facility provides a historical representation of that room. The microbes that flow throughout the air will eventually collect in the dust. Our lab has come up with a series of easy-to-use testing kits that can be found on our online store. These kits help guide homeowners or first-time inspectors through the process of sample collection to ensure they use the proper sample shipment methods. Examples of these testing kits include The ERMI, The Big 2, The SIM, and the CAP 15 analysis. See more of our testing kits on our Online Store: https://assuredbio.com/assured-bio-store/#dna
Air samples are collected using our patented M-TRAP® Air Sampling Cassette. These unique cassettes are commonly collected in a manner similar to everyday spore traps used by inspectors, but are analyzed via qPCR analysis instead of microscopy. Using the M-TRAP®, inspectors can now analyze DNA samples directly from the air, providing them the ability to track fungal contaminants all the way down to the species level.
Some inspectors and environmental health and safety supervisors collect samples over longer periods of time using our patented WhisperCare® Continuous Air Monitoring System. The WhisperCare® collects samples at a lower volume of air over a longer period of time, resulting in a much more detailed representation of the facility’s indoor air. The WhisperCare® has been used in commercial, industrial, and healthcare facilities to test the efficacy of cleaning protocols and air filtering products, and continues to be a groundbreaking device for the indoor air quality industry.
Bulk samples would be considered samples that are not from air or dust. Inspectors who send in bulk samples may send in samples that are directly from the job site. These could include: pieces of furniture, return filters, objects that contain mold, etc. Inspectors who choose this type of sampling may be working on custom projects or are interested in analyzing the species level of an already confirmed sample of mold.
When analyzing the report, it is very important to factor in your collection method. Dust and swab samples are considered historical samples and are good for assessing the mold burden over the time that the dust has accumulated. M-TRAP® cassettes assess the exact point in time the air is pulled through them. View the time you pull them as a “snapshot” of the air quality during that exact time. Reports interpreted through qPCR are much more sensitive and precise than traditional microscopy analyses and analyze the genetic content of each spore. As stated before, surface sample results can potentially spike in areas where mold growth is present. Ensure that you consult with an Assured Bio staff member about sample collection before you begin. Our lab also provides over-the-phone consultation to help guide you through the findings of your report. To learn more about our fungal qPCR testing capabilities, follow us on our Facebook and LinkedIn and keep up with our Microbial qPCR posts or visit our explore our DNA Analytical page: https://assuredbio.com/lab-services/dna-mold-diagnostics/