1. Sampling Overview
    1. Culturable air samples
    2. Non-culturable air samples
    3. Surface samples
    4. Special cases
  2. Interpretation Overview
    1. Activity levels
    2. Weather conditions
    3. Condition of the area sampled
  3. Additional Information
    1. Spore trap air sampling
    2. Andersen or Biocassette air sampling
    3. Surface sampling (Tape, Swab, Bulk)
    4. Surface sampling (Dust)
  4. Environmental Reporter
  5. Ask Dr. Burge
  6. Allergen Glossary
  7. Food Microbiology Glossary
  8. Fungal Glossary
  9. Resources
 

Andersen or BioCassette™ (Culturable) Air Sampling

Objective

To capture and quantify the different culturable fungal spores present in the air.

To determine whether the levels present indicate a fungal problem in the indoor locations.

Advantages and Disadvantages

Advantages

Culturable sampling allows for the differentiation of Aspergillus and Penicillium, standard speciation of Aspergillus and speciation of other fungi when required.

It also provides counts indicative of how many spores are culturable and present in the air.

It assess the viability of many fungi. This can be critical in certain situations when severely immunocompromised people are present.

Disadvantages

Culturable sampling methods require that the spores in the air are alive, survive the sampling process, germinate on the sampling media, and compete well with other species present on the growth media.

Culturable sampling does not indicate the presence of non-culturable spores, which may also be capable of producing allergies or irritation.

Culturable sampling also requires five to seven days for incubation after the sampling has taken place (for malt extract agar, other agars generally take longer).

Equipment

Andersen sampler and agar filled petri dishes, or

BioCassette™ and 28.3 lpm sampling pump, or

Other culturable air sampler like RCS, SAS, Microflow airsampler, etc., and

Dry gas meter for calibration.

Pump Calibration

Before sampling, always make sure the sampling pump has been periodically recalibrated using a dry gas meter to 1 ACFM.

Sampling protocols

Sampling locations should include problem areas, an indoor non- problem area if available, and an outdoor sample (or samples) for interpretation.

Air sampling data represents a specific moment in time and field observations are of equal importance. Noting items such as weather, activity levels, HVAC operation, and how accessible the outside air is (e.g. nearby windows and doors to the outside) will be helpful in interpreting the results.

Sampling at multiple times may be helpful.

Environmental conditions

Recommended sampling time at 28.3 liters per minute

Dusty, dirty, visible particles in the air

1 minutes

Normal office

2-3 minutes

Very clean

4-5 minutes

Media

There are a variety of media types available to suit particular sampling objective.

Unless specific fungi are of special concern, the media used should support a wide variety of common fungi.

Media Commonly Used

Purpose

Malt Extract Agar (MEA)

For isolating a broad-spectrum of indoor and outdoor fungi

Dicholoran-Glycerol Agar (DG-18)

For isolating the xerophilic fungi (require low water activity for growth).

Shipping

Samples should be sent to the laboratory within 24 hours using an overnight courier and packed with care to prevent breakage and contamination.

Unless samples will see high heat for an extended time, e.g stored in a car in the hot summer for several hours, cold packs should not be used.