The isolation of Escherichia coliphage by means of cationic detergents.

The action of synthetic detergents upon several strains of bacteriophage has been mentioned in a previous communication (Klein et al., 1945). With the exception of gamma coli phage, the bacteriophages tested were highly susceptible to the germicidal activity of the various test compounds. The gamma phage, on the other hand, proved to be resistant to the highest concentrations of the detergents tested. Because of this marked resistance of the gamma coli phage, various cationic detergents were used in attempts to isolate coli phage directly from sewage. Primarily, we were interested in ascertaining whether or not a coli phage may be isolated without the use of filtration.