The proposed research is designed to further evaluate and answer critical questions regarding the concept of using the zona pellucida as a target antigen for immunocontraception. Part 1 involves the active immunization of mice with isolated pig zonae pellucidae and observing what effect these immunizations have on fertility. The mouse anti-pig isolated zone sera will be evaluated in regards to titer and tissue specificity in addition to determining the duration and magnitude of the anti-fertility effect produced by these antibodies. Antibody activity against zona will be monitored by standard tests such as observing the antibody-produced precipitation layer on the zona and the indirect fluorescent antibody technique. Part 11 involves the biochemical purification of the zona antigen(s) using chomatographic and electrophoretic techniques and biochemical characterization of the purified components. The pig ovary will be the source of starting material and an RIA procedure we have developed will be used to monitor zona pellucida components during the purification protocol.