RADIOIMMUNOLOGICAL ASSAY FOR NATURALLY-OCCURRING INSECT JUVENILE HORMONES USING IODINATED TRACERS - ITS USE IN THE ANALYSIS OF BIOLOGICAL SAMPLES

Three sensitive and specific-radioimmunological assays (RIA) using iodinated tracers have been developed for the quantitative measurement of naturally occurring juvenile hormone (JH). The antigens were prepared by binding the JH's to human serum albumin. Iodinated tracers were prepared by binding histamine to the JH molecule, and then subsequently binding one molecule of 125I per molecule of histamine. The RIA's were carried out in 0.02 M phosphate buffer containing 0.1 p. 100 of BSA. The assay detection limit was 20 pg for all the three juvenile hormones. RIA sensitivity (at B/BO = 50 p. 100) of JH1, JH2, and JH3 was 0.75, 1 and 2.6 ng/ml, respectively. Antiserum to JH1 cross-reacted 7.3 p. 100 with JH2 and 0.8 p. 100 with JH3; antiserum to JH2 cross-reacted 26 p. 100 with JH1 and 12 p. 100 with JH3, and antiserum to JH3 cross-reacted 0.3 p. 100 with JH1 and 0.9 p. 100 with JH2. Various methods of preparing biological samples for the RIA of JH's have been described.