Pasteur Laboratory
                                        Sampling Methods  

Determining types and amounts of various fungal propagules present in the air and on the surface allows for assessment of active growth of fungi within the living area. Sampling procedures should include a variety of sample types to reach a solid assessment. Fungal air sampling method should include air monitoring in selected problem and non-problem areas with an outdoor comparison sample. Areas of visible fungal growth may be sampled directly by collecting bulk, tape, swab or settle dust samples and sent to the laboratory for proper identification. Culturable and non-culturable methods have their own advantages and disadvantages and each method will detect major problems.  A combination of both culturable and non-culturable methods provides the most reliable results.   

Non-culturable or non-viable bioaerosol (Sporetrap):  

Non-culturable or non-viable bioaerosol (Sporetrap):   Non-culturable air samples or sporetrap are collected using a variety of  air samplers such as Zefon Air-O-Cell, Allergenco, Burkhard, Micro 5, Cyclex-D, etc. Spore trap provides a relatively simple and cost-effective way to determine concentration of fungal spores as well as pollen, insect parts, mites, skin cells, carbon particles, and fiber glass in air samples. Spore trap allows speedy analysis when needed and effectively determines the levels and numbers of various spore types to genus or broad category. Air is drawn across a specialized adhesive cover slip, impacting and trapping all particulate matter in the air. After collecting, sample is labeled with sample number and other information (date of collection, project name and number, location of the sample, sampling time and flow rate, etc.) on the chain of custody (CoC) form and sent to the laboratory. At the laboratory, an experienced mycologist/microbiologist will identify and count the fungal spores using a microscope and the results will be presented as total number of spores per cubic meter of air.
Surface sampling:

Tape lift:  

This method involves applying a clear tape directly to the surface of visible or suspected fungal growth. A piece of transparent tape (1.5 inch long) is used. One end is folded over to provide a handle and press the sticky surface using a light pressure against the suspected area. The tape is then placed on a plastic bag or mount on a glass slide. After collecting, sample is labeled with sample number and other information (date of collection, project name and number, location of the sample, etc.) on the chain of custody (CoC) form and sent to the laboratory for identification. One disadvantage of tape lift is that they cannot be cultured. The sample is analyzed in the laboratory by direct microscopy.  
Bulk samples:  

Any piece of material (wood, drywall, carpet, insulation, ceiling tile, etc.) or contents (clothing, paper, book, shoe, etc.) with visible or suspected fungal growth can be collected for analysis. Samples should be sealed into a clean, sterile plastic bag. After collecting, sample is labeled with sample number and other information (date of collection, project name and number, location of the sample, etc.) on the chain of custody (CoC) form and sent to the laboratory for identification. One advantage of bulk sample is that they can be cultured. The sample is analyzed in the laboratory by direct microscopy or they can be cultured using different types of nutrient media.  
Swab:  

This method involves using a sterile swab to collect a sample from a suspected surface. The sterile swab is removed from its packaging and can be moistened with the holding medium in the tube before using on dry surface. The swab is then placed onto the suspected area (usually 1 to 100 square cm area) and rolled to allow to a sufficient amount of material to collect on the swab tip. The swab is then inserted back into the medium tube and tightly sealed.  Swabs are useful for wet surfaces where material will not adhere to the tape or in hard to access places. After collecting, swab sample is labeled with sample number and other information (date of collection, project name and number, location of the sample, etc.) on the chain of custody (CoC) form and sent to the laboratory for identification. One advantage of swab sample is that they can be cultured. The sample is analyzed in the laboratory by direct microscopy or they can be cultured using different types of nutrient media. 
Culturable or viable bioaerosol:

This method involves drawing an air sample over a Petri dish containing nutrient agar culture media. The most common type of sampler is the vacuum pump sieve-impaction samplers (such as Andersen N6, a high-volume vacuum pump calibrated to a flow rate of 28.3 liters per minute). Other sieve impactors have higher flow rates, such as Surface Air System (SAS Super 100), Millipore MAirT, and the EM Science MAS 100.These samplers use standard 10 mm Petri plate or contact plates for impaction. After collecting, the cover is replaced and the culture plate sample is labeled with sample number and other information (date of collection, project name and number, location of the sample, sampling time and flow rate, etc.) on the chain of custody (CoC) form. The plates are sealed with parafilm. At the laboratory, an experienced mycologist/microbiologist will identify the fungal colonies and the results will be presented as colony forming unit or CFU per cubic meter of air. Agar plates containing nutrient media are available from Pasteur Laboratory at no cost.
About Us
Services
Sampling Methods
Chain Of Custody
Useful Links and Resources
Common Fungi and Their Health Effects
Contact Us