Abstract
Two methods for selection of mutagenic and phage inducing agents on plates have been described. The first method depends on the mutation of T2 phage from h+ to h; the mutation is detected by the appearance of plaques around the diffusion area of the sample. The second method is based on the liberation of λ phage from a lysogenic strain of E. coli; the induction is detected by the appearance of a turbid circle around the sample. The two methods are quite simple and directly applicable for selection of strains which produce mutagenic or phage inducing substances. Application of these methods as screening methods for selecting anti-tumor agents have also been discussed.
