This antibody recognizes the D1 domain of an N-glycosylated glycoprotein of 120kDa with intra-chain disulfide bonds, identified as CD50 or ICAM-3. CD50 is the major ligand for LFA-1 (CD11a/CD18) and may have signaling role to increase adhesion. It is expressed on thymocytes and T lymphocytes and is resistant to treatment with phosphatidylinositol (PI) phospholipase C. This MAb is excellent for staining of formalin/paraffin tissues.