The HSE has released a research report (RR1191) into a commercially available method of identifying asbestos fibres. Three commercially available FM kits of the same type were obtained and tested.
Researchers in Japan have developed a method for measuring fibres in air which uses fluorescence microscopy. Different types of proteins have been engineered to selectively bind to asbestos fibres leaving other mineral fibres and particles unaffected. The principle is that air sampling filters are treated with a solution containing fluorescent marker labelled proteins. When observed under FM, all asbestos fibres should fluoresce, with other material and non-asbestos fibres remaining dark.
Health and Safety Executive
You can view the full research report at the HSE website.