Fluorescent method for the detection of excreted ribonuclease around bacterial colonies.

Lanyi, Janos K. (Stanford University School of Medicine, Palo Alto, Calif.), and Joshua Lederberg. Fluorescent method for the detection of excreted ribonuclease around bacterial colonies. J. Bacteriol. 92:1469-1472. 1966.-A test for the release of extracellular ribonuclease by Bacillus subtilis colonles was developed. The method consists of incorporating acridine orange and ribonucleic acid into nutrient agar plates and viewing the grown bacterial colonies under ultraviolet light. Regions of ribonuclease secretion appear as dark halos around the colonies on a green fluorescent background. The theoretical basis and the utility of this test are discussed.