The production of monoclonal antibody to androstenedione and the effect of passive immunization on Xinjiang fine-wool sheep with it.

Five hybridomas stably secreting monoclonal antibodies (McAbs) to androstenedione were prepared by using artificially synthesized androstenedion-11 alpha-succinyl conjugate with bovine serum albumin (BSA) as antigen. These McAbs showed slightly high cross-reactivity with testosterone (8.1-12.3%) and estrone (0.8-2.5%) and high affinities ranging from 2.0 x 10(7) to 2.8 x 10(8) L/M. They were all of the IgG1 subclass. Xinjiang finewool ewes which were passively immunized with McAbs had higher circulating levels of progesterone (P) and luteinizing hormone (LH) than those of control ewes in two oestrous cycles and these changes led to increased ovulation rate and twin lambs born in young ewes.