Description
When studying staphylococci, Wechman and Catlin1 concluded that there was a close correlation between coagulase production and DNase activity, and suggested that a test to detect this phenomenon could be used for the identification of pathogenic staphylococci.
Jeffries et al incorporated DNA into an agar plate, however the semi-synthetic medium that he used did not support many fastidious organisms2.
Di Salvo3 added DNA to Trypticase Soy Agar and demonstrated complete agreement with the results of Weckman and Catlin. He also added calcium chloride to the medium to activate bacterial desoxyribonuclease however, Fusillo confirmed that the calcium content of the medium was already adequate4.
DNase activity was demonstrated by flooding the plate with 1N HC1 and looking for zones o clearing around colonies.
