1. A mouse hybridoma secreting an antibody directed against human renin was obtained by fusion of spleen cells with NS 1 myeloma cells. This monoclonal antibody recognizes human and monkey renins but neither hog nor mouse renins nor the acid proteinase cathepsin D.
2. Monoclonal antibody was coupled to Sepharose 4 B. The immunoadsorbent thus obtained was very efficient in purifying both active and inactive human renin from renal or extrarenal sources.
3. Renin enrichment up to 3500-fold was obtained in a single step.