USE OF NEUTRAL RED FLUORESCENCE FOR THE IDENTIFICATION OF COLONIES OF CLOSTRIDIA
Abstract
Receive: RSS Feeds, eTOCs, free email alerts (when new articles cite this article), more» Information about commercial reprint orders: http://jb.asm.org/site/misc/reprints.xhtml To subscribe to to another ASM Journal go to: http://journals.asm.org/site/subscriptions/ USE OF NEUTRAL RED FLUORESCENCE FOR THE IDENTIFICATION OF COLONIES OF CLOSTRIDIA1' 2 LEO KAUFMAN AND R. H. WEAVER Department of Bacteriology, University of Kentucky, and Kentucky Research Foundation, Lexington, Kentucky Received for publication July 22, 1959 In a study of indicators for acid production by clostridia we discovered that neutral red was transformed to a fluorescent substance by all of the strains used, even when no acid was produced. This suggested its use for the recognition of primary isolation colonies. Preliminary studies showed the fluorescent substance to be produced in liver veal agar (Difco) by clostridia, but not by any of the facultative aerobes or facultative anaerobes tested. The minimal concentration that would allow the production of good fluorescence, 0.004 per cent, did not appear to be bacteriostatic for any of the strains. When plates were poured from sources that contained both clostridia and facultative anaerobes, fluorescent areas appeared on the plates but isolated colonies could not be obtained because of spreading growth. Several procedures were tried