CD45 Antibodies

CD45 is a protein tyrosine phosphatase regulating src-family kinases which is expressed on all hematopoietic cells. CD45 can be expressed as one of at least five isoforms (from 180 to 220 kDa) by alternative splicing of exons that comprise the extracellular domain. The non-restricted CD45, Leucocyte Common Antigen (LCA) consists of an extracellular sequence, proximal to the membrane, which is common to all CD45 isoforms. All the monoclonal antibodies that belong to the CD45 cluster react with this part of the antigen and are able to recognize all CD45 isoforms. The non-restricted CD45 epitope is present on the surface of all human leucocytes, lymphocytes, eosinophils monocytes, basophils and neutrophils by order of decreasing level of expression. It is absent from erythrocytes and platelets. It is lost during maturation of erythroid cells in the bone marrow. CD45 antibodies react with leucocyte progenitors in bone marrow.