Hello,

CD45 (Leukocyte Common Antigen) is expressed on every normal leukocytes from blood. The normal range of CD45+ cells is your leukocyte's normal value's range. (Variations depend mainly on the age). (Blood: 4.000-10.000 leukocytes/µL for adult subjects)

If you're asking for the absolute count of binding site on the surface of the leukocytes, it depends on the kind of cell, clone,...you target