Cedarlane'spurified anti-CD8a (Ly 2) monoclonal antibody reacts with a protein ofapproximately 30 kDa found on mouse thymocytes and mouse cytotoxic/suppressor Tcells. It does not bind to mouse helper/inducer T cells. It binds to T lymphocytesfrom all mouse strains regardless of phenotypic expression (i.e. reacts with Tlymphocytes from mouse strains expressing the Ly 2.1 or Ly 2.2 phenotype). Itcan be used to investigate the role of T cells in models for infectiousdisease, autoimmunity, transplantation tolerance and fundamental aspects ofimmunology