If so, can you offer some help with a source for a stain that will work? Hello Bill, This is because they are using a fluorescent microscope using UV light, in this case the die is for exemple calcofluor white https://www.sigmaaldrich.com/catalog/product/sial/18909?lang=fr®ion=FR&gclid=EAIaIQobChMI3JyxsIHx4AIVElXTCh2YtgzmEAAYASAAEgKTXPD_BwE But if you are using a standard microscope such as Randy explained us, you need instead to counterstain, so the spores appear transparent. Georges *********************************************** The BEE-L mailing list is powered by L-Soft's renowned LISTSERV(R) list management software. For more information, go to: http://www.lsoft.com/LISTSERV-powered.html