The Science

What is MSQPCR?

MSQPCR represents a significant leap in mold detection and quantification techniques, addressing the shortcomings of traditional methods like culturing on media and visual spore counting. This highly sensitive molecular technique utilizes unique DNA sequences to identify molds accurately, providing a much-needed objective approach in environmental sample analysis. The process begins with efficient sample preparation, including bead-beating DNA extraction from air or dust samples, followed by purification and the application of quantitative PCR. This advancement not only streamlines the detection process but also enhances its specificity and reliability.

The incorporation of dual fluorescently labeled DNA probes into the PCR process marks a pivotal improvement, enabling species-specific identification of molds. This precision is critical in various applications, including home environment assessments and broader epidemiological studies. By quantifying mold presence directly from DNA, MSQPCR mitigates the subjective errors inherent in manual spore counting, offering a quantifiable, objective measure of mold populations. This methodology is instrumental in analyzing mold dynamics, particularly in residential settings where understanding the impact of moisture and water intrusion is crucial.

MSQPCR's utility extends beyond residential mold detection, proving invaluable in healthcare settings for monitoring nosocomial fungal infections and in agriculture for tracking plant pathogens and mycotoxin-producing fungi. The technique's sensitivity and speed facilitate real-time surveillance of potentially pathogenic molds, crucial during hospital renovations or in agricultural produce storage. By enabling rapid, accurate assessments, MSQPCR assists in preemptive measures against mold-related health risks, enhancing environmental and food safety.

Moreover, the rapid turnaround time of MSQPCR assays, often within approximately three hours, contrasts sharply with the protracted timelines of traditional culturing methods. This efficiency, coupled with the technique's high specificity and capacity for broad application, underscores its revolutionary impact on environmental mold analysis. The advancement of MSQPCR, supported by the U.S. EPA and implemented through licensed companies, signifies a major stride toward understanding and mitigating mold's adverse effects on health and property.

How do we use MSQPCR?

The Dust Test utilizes mold-specific quantitative PCR (MSQPCR) technology as a screening tool to identify the top 36 different species as well as toxins produced by both molds and bacteria that typically inhibit unhealthy homes, depending upon the test you select.

MSQPCR obviates the limitations of these century-old methods of detecting and quantifying molds. MSQPCR is objective and specific because it is a detection system based on unique DNA sequences.

Learn More: You can learn more on MSQPCR Technology by American Laboratory's research "Mold-Specific Quantitative PCR: The Emerging Standard in Mold Analysis" found here.

How widespread is mold in homes?

In 2004, the Department of Housing and Urban Development’s (HUD) commissioned the first American Healthy Homes Survey (AHHS I), which sampled 1,096 homes selected to be representative of the U.S. housing stock. In AHHS I, a dust sample from each home was analyzed using quantitative PCR assays (qPCR) for 36 common indoor molds: 26 Group 1 molds, which were associated with water damage in homes and 10 Group 2 molds, which primarily enter the home from the outside environment.
In 2019, HUD completed a second American Healthy Homes Survey (AHHS II) to track changes in the condition of the U.S. housing stock. One of our goals was to examine the stability of the ERMI scale in U.S. housing over time. Another goal was to document changes in mold contamination in homes built before 1978, the year lead was banned from paint in the U.S. (U.S. Consumer Product Safety Commission 1977).

The results were staggering!

Between 2004 and 2019, 34 out of 36 species showed an increase in prevalence of mold contamination in the sampled homes.

The AHHS II concluded:

"By using the ERMI metric, we were able to demonstrate that water damage and mold growth were more likely to occur as homes get older."

Read More: You can learn more about the American Healthy Homes Survey (AHHS II):

"The Environmental Relative Moldiness Index reveals changes in mold contamination in United States homes over time" here.

Below, you will find a summary of the occurrence in mold species from AHHS I to AHHS II.

Mold species in Groups % %
Occurance Occurance
Group 1
Aspergillus flavus 36 47
Aspergillus fumigatus 62 70
Aspergillus niger 69 97
Aspergillus ochraceus 27 74
Aspergillus penicillioides 90 99
Aspergillus restrictus 12 76
Aspergillus sclerotiorum 26 54
Aspergillus sydowii 29 6
Aspergillus unguis 20 36
Aspergillus versicolor 30 70
Aureobasidium pullulans 94 100
Chaetomium globosum 51 72
Cladosporium sphaerospermum 82 98
Eurotium amstelodami 98 100
Paecilomyces variotii 46 64
Penicillium brevicompactum 52 89
Penicillium corylophilum 17 68
Penicillium group 2 8 63
Penicillium purpurogenum 15 25
Penicillium spinulosum 20 5
Penicillium variabile 50 87
Scopulariopsis brevicaulis 53 64
Scopulariopsis chartarum 38 75
Stachybotrys chartarum 35 38
Trichoderma viride 27 78
Wallemia sebi 75 100
Group 2
Acremonium strictum 57 82
Alternaria alternata 88 100
Aspergillus ustus 40 60
Cladosporium cladosporioides 1 99 100
Cladosporium cladosporioides 2 70 95
Cladosporium herbarum 84 99
Epicoccum nigrum 93 98
Mucor racemosus 92 97
Penicillium chrysogenum 2 66 95
Rhizopus stolonifer 29 52

Mold species in Groups
Group 1   
Aspergillus flavus364730.56%
Aspergillus fumigatus627012.90%
Aspergillus niger699740.58%
Aspergillus ochraceus2774174.07%
Aspergillus penicillioides909910.00%
Aspergillus restrictus1276533.33%
Aspergillus sclerotiorum2654107.69%
Aspergillus sydowii296-79.31%
Aspergillus unguis203680.00%
Aspergillus versicolor3070133.33%
Aureobasidium pullulans941006.38%
Chaetomium globosum517241.18%
Cladosporium sphaerospermum829819.51%
Eurotium amstelodami981002.04%
Paecilomyces variotii466439.13%
Penicillium brevicompactum528971.15%
Penicillium corylophilum1768300.00%
Penicillium group 2863687.50%
Penicillium purpurogenum152566.67%
Penicillium spinulosum205-75.00%
Penicillium variabile508774.00%
Scopulariopsis brevicaulis536420.75%
Scopulariopsis chartarum387597.37%
Stachybotrys chartarum35388.57%
Trichoderma viride2778188.89%
Wallemia sebi7510033.33%
Group 2  
Acremonium strictum578243.86%
Alternaria alternata8810013.64%
Aspergillus ustus406050.00%
Cladosporium cladosporioides 1991001.01%
Cladosporium cladosporioides 2709535.71%
Cladosporium herbarum849917.86%
Epicoccum nigrum93985.38%
Mucor racemosus92975.43%
Penicillium chrysogenum 2669543.94%
Rhizopus stolonifer295279.31%