Air Sampling

A. Spore trap method-different air samplers used to collect particles from the air into cassette or slide.

B. Viable method-different air samplers used to collect biological particles into selected agar media.

Examples of pumps used for non-viable air sampling methods:

1. The Zefon Air-O-Cell Cassette Particle Sampler requires an external pump. The manufacturer recommends a 15LPM flow rate.

2. Cyclex and Cyclex D (flow rate is 20LPM).

3. Micro 5 (flow rate is 5LPM).

4. Laro-100 (flow rate is 4LPM)

5. The Burkard Personal Spore Trap contains an internal pump that samples at 10LPM. In a routine environment, this pump is set for 9 minutes for a total volume of 90 L. In any analysis situation that is expected to be heavily contaminated with fungal spores the time of sampling should be decreased.

6. The Allergenco, which can provide multiple time-differentiated tests on the same slide, has an internal pump calibrated at 15LPM. The time can be set for anywhere from 6 min for a total volume of 90 L to 10 min for a total volume of 150 L.

7. The BioSIS 2000 is a slit impaction sampler that also impinges the air on a sticky glass slide.


1. These pumps will collect both viable and non-viable particles but the laboratory will report only non-viable due to lack of the presence of the Fungal Fruiting structures.

2. LPM= Liter Per Minute.

Examples of pumps used for viable air methods:

1. Andersen impactors. Recommended flow rate is 28.3LPM.

2. SAS. Recommended flow rate is 90 LPM.

3. All Glass Impinger. Recommended flow rate is 12.5 LPM.

4. Biotest strips air samples. Recommended flow rate is 100 LPM.


The Air-O-Cell is a unique sampling cassette specifically designed for the rapid collection and quantitative analysis of a wide range of airborne aerosols. It collects both viable and non-viable particulates such as mold spores, pollen, insect parts, skin cell fragments, fibers, and inorganic particulates.


1. Useful for initial indoor air quality (IAQ) survey of the biological particulates in the air.

2. East to get quick turn around time.

3. Chance of sample contamination is low.

4. Easy to operate.


1. Cannot be cultured.

2. Fungi cannot be separated to the species level.

3. Penicillium/Asperigllus cannot be differentiated due to similarity in size and color.

Recommended Sampling Intervals for the Air-O-Cell Sampling device at Typical Collection Flow Rates( 15 PLM).

 Typical Environmental ConditionsFlow ratetd
1Clean “office” or outdoors (no visible dust)10 Minutes
2Indoor environment, high activity & personnel5 Minutes
3Indoor environment, drywall renovation or heavy industrial dust2 Minutes
4Outdoor environment5 Minutes

Recommended sampling procedures

1. Calibrate the pump to 15 LPM.

2. Remove the tape seals covering the inlet and outlet and placed them on the side of the cassette.

3. Connect the Air-O-Cell cassette to the sampling pump using flexible tubing.

4. Turn the sampling pump on for an appropriate sampling time range from 1 to 10 minutes.

5. After sampling is complete, return the tape seals back.


The Laro 100 air-sampling cassette is an ideal method to analyze personal exposure to mold. Mold spores are collected on 0.8 micron mixed cellulose ester filter (like an asbestos PCM cassette). It is capable of capturing 100% of all airborne fungal particulate as well as any particulate or fibers 0.8 microns and greater in size. The sample can be analyzed immediately after collection by optical microscopy.. Overloading the sample can be a problem in dirty environments. Blank samples and outdoor control samples should be submitted with the personal samples. Laro 100 samples can also be cultured by dissolving the filter in water, extracting the water, and culturing the water on an agar plate.

 Environmental situationFlow rate/Sampling time
1Inside/Outside-with no visible particulate in the air4 L/min /10 min or longer
2Special inside clean environments4 L/min / 30 min or longer
4Inside-8 hr /personnel monitoring1.0 – 2.0 L/min / to obtain 300-480 L.


1. Laro 100 strip is the only one can be cultured.

2. Differences between these pumps are: Flow Rate & Efficiency in collecting different sizes of the fungal spores.

Micro 5

The Micro5 Microcell airborne mold-monitoring cassette is another method to analyze personal exposure to mold. The Micro5 cassette contains a glass slide with adhesive that captures the mold spores when they impact the slide. The Micro5 has a 50% collection efficiency of 0.8 microns at 5 liters per minute. Micro5 samples can be analyzed immediately after collection by optical microscopy. The flow rate for the Micro5 must be set at 5 liters per minute to obtain a target sampling volume of 25 liters. Like the Laro 100, overloading the sample can be a problem in dirty environments. Blank samples and outdoor control samples should be submitted with the personal samples. The weakness of this method is the short time duration used to collect the sample. A five-minute sample may not give an accurate exposure concentration for an eight-hour workday. In order to collect 8 hours of sampling data, 96 samples would need to be collected.

 Typical Environmental ConditionsFlow ratetd
1Clean “office” or outdoors (no visible dust)5 Minutes
2Indoor environment, high activity & personnel3 Minutes
4Outdoor environment3 Minutes

Andersen Impactor

PURPOSE: Identification of culturable microorganisms and assessment of possible proliferation and dissemination of bacteria or fungi from building reservoirs.


1. Samplers.

Andersen 2-stage cascade impactor.

Andersen N-6 single-stage sampler.

2. Sampling media, in plates prepared according to sampler manufacturer’s recommendations:

Malt extract agar (MEA) for fungi.

Trypticase soy agar (TSA) for mesophilic bacteria and thermophilic actinomycetes.


Other media may be used, if appropriate, e.g., dichloran glycerol agar (DG18) for xerophilic molds, R2A agar for heterotrophic bacteria, and cellulose agar for Stachybotrys chartarum.

3. Sampling pump capable of meeting sampler manufacturer’s flow specification (e.g., 28.3 L/min), with flexible connecting tubing.

4. Cotton gauze pad, e.g., 4″x 4″.

5. Rubbing alcohol, 70% isopropanol.

6. Refrigerant packs: NOTE: Keep samples cool, but protect from freezing.


1. Select at least three sites, one each to represent complaint area, a noncomplaint area (otherwise as similar as possible to complaint area), and outdoors.

2. In turn at each site, sample simultaneously for fungi, mesophilic bacteria, and thermophilic actinomycetes. Typical sampling time is ten minutes. Before moving to the next site, repeat twice to obtain triplicate, consecutive samples.

3. Load and immediately unload one set of sampling media in each sampler to serve as field blanks.

4. Collect another complete set of samples and blanks on the next day.

SAMPLING Procedure

1. Calibrate each sampling pump with a representative sampler in line.

2. Before each run, carefully and thoroughly wipe each sampler stage with rubbing alcohol. Allow to dry. Make sure air passages are not blocked.

3. Load sampling media into sampler, remove covers from media, and attach sampler to pump with flexible tubing.Note: Take special care to prevent contamination of media during loading and unloading. Do not touch agar surface.

4. Sample at known preset flow for an accurately known time, e.g., 5 min. (In heavily contaminated areas, a shorter sampling time may be necessary.)

5.Replace covers on sampling media, unload, and pack securely.

Bacteria Sampling Instructions

Surface Sampling

Method of choice when there is visible mold growth. Done by using one of the following:

1.Tape lifts.

2 Swabs.

3. Bulk.

1.Tape lifts cannot be cultured.

2. Swabs usually use on wet surfaces.

3. Swabs are not a method of choice for surface sampling due to damage of Fungal structures(fruiting structure and hyphal fragement) during the process.

4. Can get the results by looking directly under the microscope.

Advantage of surface sampling:

1. Inexpensive method.

2. Quick Turn around time.

3. Good for Initial indoor air quality (IAQ) Fungal survey especially if visible Fungal seen.

Disadvantage of surface sampling:

1. Ignoring the spores in the air, which can be harmful.

2. Tape lifts cannot be cultured.

Tape Lifts sampling guide

1.Choose the area of most concern for testing. We suggest testing any areas with visible mildew or water damage.

2.Wear a sterilized glove.

3. Take a three-inch piece of clear scotch tape, do not use frosty tapes. Fold one end over, sticky side to sticky side, to make a 1/2-inch tab handle (this will give you something to grasp). Leave the rest of the sticky side exposed but not for a long time.

4. Gently depress the sticky side of the tape against the area you are testing, and lift the tape off. You should try to get a sample about the size of a postage stamp. More is not necessarily better as it will be observed through a powerful microscope.

5. Adhere the sticky side of the tape to the inside of the zip lock bag.

6.Tape the piece of paper with your information and sample location inside the zip lock bag. Place the zip lock bag inside a mailing envelope and mail it to the lab.

Multiple samples

should be collected for comparison studies. Currently, there are no governmental or industrial regulations concerning allowable mycotoxins or toxigenic mold spores in indoor environments. Your best insurance against potential problems is to investigate any compliant as soon as possible, identify any actual or potential fungal issues and address a remediation plan.