ABSTRACT
The antigenic and toxic properties of the crystalline proteins from two varieties of B. thuringiensis (var. galleriae and var. insectus) were studied. Methods of double diffusion in agar and two-dimensional disc immunoelectrophoresis revealed four antigens in the crystalline protein from var. galleriae and three in that from var. insectus. A definite correlation was found between the toxicity of the crystalline protein and its capacity to interact with antiserum in a precipitation reaction in agar. It was established that the total protein content cannot be used as the criterion for an evaluation of the activity of preparations from B. thuringiensis. Immunodiffusion methods are recommended for an evaluation of the quality of these preparations.