The usual method of immunoelect rophoret ic analysis of the water-soluble l iver t issue proteins was used [1-2]. After careful perfusion with a large volume of physiological saline through the blood vesse ls , the l iver t issue was cut into small pieces and ground in a mor t a r at 1-2 ~ The proteins were extractedwith isotonic sodium chloride solution (pH 8.8) in the protein of 1 : 1 . After 24 h the extract was clarif ied by prolonged centrifugation at 10,000-12,000 rpm and at 1-2 ~ Eleetrophoret ie fractionation of the extract was pe r fo rmed in 1% Difco agar at a voltage gradient of 5 V/cm for 2 h. Development of the stains p r o duced by e lec t rophores is was ca r r i ed out by means of the serum of rabbits immunized with extract of l iver t issue f rom the patients dying f rom acute hepatitis in the stage of acute atrophy. To obtain an antise rum with a high t i ter of antibodies, Freund ' s adjuvant was used. Usually a mixed ant iserum (from several rabbits) after immunization for 4-5 months was used. To detect t i ssue and organ-speci f ic proteins, the ant iserum was exhausted with se rum proteins and proteins of other organs (spleen, kidney, lungs, heart) . The se rum proteins were determined by means of ant iserum against human serum.