[A monoclonal antibody detecting human leucocyte marker-T200 antigen]

A monoclonal antibody (48)against human Pan-Leucocytes was prepared. This antibody reacted with all haemopoietic cells tested, but not with red cells and platelets by indirect immunofluorescent staining. It was also disclosed that this antibody is only bound to lymphoid tissues or leucocytes scattered in other tissues with immunoperoxidase staining. The reactivities of McAb 48 with large a mount of various target cells were identical with anti-HLE, McAb of CD45 group. Therefore McAb 48 also recognizes T200 antigen and belongs to CD45 group. The value of McAb 48 in differential diagnosis of malignant lymphoma is discussed.