FIELD: medical microbiology. SUBSTANCE: method deals with obtaining anthracic sera enabling to differentiate Bacillus anthracis against closely related microorganisms. Cell-free culture filtrate of Bacillus anthracis STI is concentrated upon ultrafilters HLP-10 and PM-10 by 150 times to achieve protein content in the filtrate being 8-10 mg/ml, then isolation of antigenic components is performed by gel filtration chromatography upon ultrafine sephacryl S-300 balanced with 0.3 M-NaCl solution with 0.025 M-tris-HCl buffer at 8.4 pH at registration of fractions' yield at λ = 280 nm. To obtain highly specific serum one should use an antigen of above 150 kDa molecular weight that corresponds to the first peak of fractions' yield. The obtained serum reacts in immunodiffusion reaction in gel with antigens of different variants of anthracic agent only that enables to identify anthracic agent against bacilli closely related according to their antigenic properties. EFFECT: higher efficiency of identification. 2 dwg, 4 ex
