This antibody reacts with the CD49b-antigen (GPIa or VLA-2 alpha-chain), which can form distinct complexes with either the CD29-antigen (GPIIa or VLA beta-chain), resulting in the VLA-2 (alpha-2 beta- 1) complex, which is expressed on human platelets. The monoclonal antibody reacts with platelets, long-term cultivated T lymphocytes and activated T lymphocytes. In immunohistology the monoclonal antibody reacts with thymocytes, epithelial cells of a variety of tissues, peripheral nerves, fibroblasts, osteoclasts, glomerular mesangium and most non-haemopoietic adherent cell lines.