FIELD: immunologic methods. SUBSTANCE: method and gel can be used in immunology to determine in vitro activity of complement according to classic activation route for different diseases that can involve complement system. Method and gel ensure prolonged stabilization of structural-functional properties of membranes of sensitized erythrocytes causing elevated resistance to nonspecific lysis and ability of membranes for complement-dependent lysis in absence of inhibiting effect on complement-dependent lysis and with homogeneity of hemolysis zone being measured. Preliminarily, gel is prepared. In the course of this procedure, selective β2- adrenomimetic is additionally introduced into suspension of sensitized erythrocytes in agarose in concentration 0.005-0.01 g/1 l of suspension. Resultant suspension is placed into vessel of transparent material forming gel in such a way that area of working surface of gel constituted no more than 16 sq.mm and height of gel exceeded normal hemolysis zone value by at least 2.5-3 times. Blood serum of patient being examined is then prepared and applied onto working surface of gel in test sample, and simultaneously standard blood serum onto that in reference sample. Test and reference samples are kept successively for 18 hr at 4 C and then for 2 hr at 37 C. Activity of complement is determined from deviation of gel hemolysis zone depth values in test and reference samples. When such value in test sample represents less than 80% of that in reference sample, complement activity is regarded as reduced; if 80 to 120%, normal; and if above 120%, elevated. Gel contains suspension of sensitized sheep erythrocytes in agarose and, additionally, β2-adreno- stimulator such as phenotherol, salbutamol, or terbutalin at following contents of components: 9.0-11.0 g/l agarose, 0.18-0.22 g/l gelatin, 176-216 ml/l barbital buffer, 8.8-10.8 ml/l cheep erythrocytes sensitized by hemolytic serum, and distilled water to 1 l. EFFECT: facilitated estimation of complement activity. 11 cl, 8 tbl, 4 ex
