From Bioscience World, Autumn 2005
IN GENERAL, TECHNIQUES OF INVESTIGATIVE MOULD SAMPLING are divided into two main categories, which indicate two very different approaches to the problem of finding out what is there and what it might be doing. These are called ‘viable’ and ‘non-viable’ sampling methods.
The term ‘viable’ is used in the aerobiological context to describe propagules (whether spores, spore-bearing structures or hyphal fragments) which will germinate and grow on some common laboratory media (and sometimes, by extension, inside people whose immune systems are deficient or compromised). These propagules are often collected by drawing air onto the surface of a plate (Petri dish) containing a solid nutritive medium.
It is clear that the so-called ‘viable’ methods will detect only a fraction of the spores in the air that are actually viable, that many of the visually identifiable spores in the air are actually non-viable, and that the results of such methods, unsupported by other approaches, is bound to be misleading. There are situations in which it matters whether the spores are alive.
There are several situations in which ‘viable’ and ‘non-viable’ methods can be truly complementary.
It is clear that both ‘viable’ and ‘nonviable’ methodologies are valuable.
For the sake of clarification, I would like to see the term ‘viable’ replaced by ‘culturable’. I would also like to drop the term ‘non-viable’, and call such tests ‘broad-spectrum’.
|Author of twelve
books including The
Fifth Kingdom, three
textbooks and over 300 other publications,
Dr. Kendrick is Technical Advisor for Aerobiology
Laboratory Associates, Inc.
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