A METHOD FOR THE DETERMINATION OF HUMAN CHORIONIC GONADOTROPHIN IN URINE EXTRACTS.

A method is described for the preparation in rabbits of a specific antiserum to human chorionic gonadotrophin. The ability of this antiserum to fix complement in the presence of urinary human chorionic gonadotrophin is demonstrated. The standardization of antiserum against the international standard preparation of human chorionic gonadotrophin, the determination of antiserum specificity using appropriate controls, and the value of antiserum in the diagnosis of pregnancy and conditions associated with high urinary levels of human chorionic gonadotrophin is emphasized.By the complement-fixation test it is possible to detect a minimum of 1.5 international units of human chorionic gonadotrophin contained in 0.1 ml. of a 1 in 2 dilution of urine extract. In the Hogben pregnancy test, using 2.5 ml. of urine extract per animal, a minimum concentration of 70 international units of human chorionic gonadotrophin is required to give a positive response. The ease and economy of the complement-fixation test are described and results are compared with those of the Hogben test.