D058-1283 is a CD45 monoclonal antibody specific for non-human primate leucocytes. It was developed using Rhesus peripheral whole blood as the immunogen. It does not cross-react with human leucocytes. This antibody reacts with baboon, Rhesus and Cynomolgus Macaque leucocytes in a similar pattern to CD45 binding to leukocyte common antigen (LCA) on human cells. Immunophenotypic analysis shows that D058-1283 binds to lymphocytes, monocytes and granulocytes of non-human primate blood samples. This antibody is able to block the binding of monoclonal antibody TÜ116; a reported anti-human CD45 antibody that cross-reacts with nonhuman primate leucocytes. In Western blot analysis, the D058-1283 antibody identifies a 180-200 kDa band.