[Ultramicromethod of determining antigens].

A method of alpha-fetoprotein (AFP) ultramicrodetection, permitting to reveal up to 10(--8) mg of AFP with its concentration of 1--2.10(--6) mg/ml was suggested. The antigen ic concentrated in a capillary tube during the electrophoresis in polyacrylamide gel. The compressed zone moves into the gel plate, containing antiserum. Free diffusion of the antigen is followed by the formation of precipitation rings, whose area is in proportion to the amount of the antigen. The precipitins are revealed by the treatment with I125-labeled antibodies to gamma-globulin of the immune serum, with subsequent radioautography.