EN
To carry out determinations of the pregnant mare's serum gonadotropin (PMSG) by means of immunological reaction, an immune serum was produced on rabbits and then lyophylized. The antiserum was used for determination of the PMSG content in the serum of pregnant mares and in preparations containing PMSG at application of the test of agglutination inhibition of the Bacto-latex 0.81 coated by PMSG. To accomplish this test, the rabbit antiserum, the coated latex and the fluid or serum investigated, were used. The readings were made after 24, 48 and 72 hours, at the assumption that the maximal dilution of the fluid investigated, in which agglutination precipitate appears, would correspond with 14 i.u. of PMSG per 1 ml of the fluid. In determinations of the PMSG activity the results approximating (± 3-5%) the declared amount of international units of the PMSG in the products investigated have been obtained.