A New Application of the PCM Method Used for Asbestos in Air Samples to Prepare Reference Slides for Mold Spores
Bharati Lakshmi and Gillian Jones
Marine Chemist Service, Inc., 11850 Tug Boat Lane, Newport News, VA 23606-2527
Environmental microbiology laboratories are required to identify and count mold spores during non-viable spore trap analysis. It is desirable to have a set of reference slides to facilitate mold spore identification. Here we report a simple method for making permanent slide mounts of mold spores.
Frequently during the air sample analysis for asbestos fibers by Phase Contrast (PCM) technique (NIOSH 7400), we notice mold spores. These observations prompted us to prepare mold spores collected from known fungi following the method used in PCM analysis. The spores were lightly spread on the Mixed Cellulose Ester (MCE) filters taken from PCM cassettes. The filter was cleared using acetone vapors injected through a “Quick Fix” commonly used in asbestos laboratories. Later, the filters were mounted in triacetin. Slide mounts of materials containing spores like Chaetomium sp., Stachybotrys sp., and basidiospores showed very good resolution. These slide mounts can be easily stored for a long period of time.
This technique provides an easy and simple method for laboratories currently analyzing asbestos by PCM to make a collection of known mold spores to be used as reference slides.
For the complete whitepaper, please contact Dr. Lakshmi.