In food microbiology the tube coagulase is the gold standard- it's in the Australian standard method anyway- even with overnight incubation! Ian Dilworth wrote in message <3a9bcb0f$0$46005$1dc6e903 at news.corecomm.net>... >No one has commented on my biggest question - ARE YOU USING TUBE COAGS >TO CONFIRM THAT THESE ARE INDEED STAPH. AUREUS?