Production of antisera against electrophoretically separated relaxin and immunofluorescent localization of relaxin in the porcine corpus luteum.

Antisera to porcine relaxin were produced in rabbits injected with different fractions that had been separated by polyacrylamide gel electrophoresis (PAGE). Analyses by agar double immunodiffusion demonstrated that the different fractions of relaxin separated by PAGE have similar antigenic sites and the individual fractions are indistinguishable from one another by this procedure. Antiserum to porcine relaxin inhibited the interpubic ligament forming ability of the hormone in vivo. Indrict fluorescent antibody studies demonstrated that the hormone was localized only in the corpus luteum of the pregnant sow ovary. Large ovoid or polyhedral cells, assumed to be granulosa lutein cells, exhibited the heaviest fluorescence.