FIELD: virology. SUBSTANCE: for determination of interferon, delay of cytopathogenic effect of test-virus in tissue culture grown on polystyrene plates is utilized. One-time diluted infant material under study is added to grown tissue culture and incubated for 18 hr at 37 C in atmosphere containing 3% carbon dioxide. Culture is further infected with Sanday virus at concentration 107, and 18 hr later, under the same incubation conditions, Guinea pig erythrocytes are sorbed on infect culture layer. Erythrocytes are then lysed with water, 0.06% o-phenylenediamine solution mixed with 3% hydrogen peroxide is added into sockets, and 20 min later reaction is stopped with 1 N sulfuric acid, after which results are recorded on immunoenzymatic analyzer. Activity of interferon is estimated from the level of drop of values in sockets with materials being studied compared to reference data. EFFECT: increased accuracy in determination of interferon titer. 2 tbl
