Rat lymphocyte differentiation antigens detected by rabbit antiserum to thymocytes and leukaemic cells.

The lymphocyte differentiation antigens detected by rabbit antisera to rat thymocytes and leukaemic cells have been investigated. Thy-1 was the only such antigen detected by the anti-thymocyte serum, which was predominately directed to two xenoantigenic determinants rather than the Thy-1.1 determinant on this molecule. Two additional antigens were recognized by the anti-leukaemia serum. One of these was found on thymocytes and peripheral lymphocytes, but only on 1 per cent of bone marrow cells. The other was found not only on lymphocytes, but also on the nucleated myeloid and erythroid cells of bone marrow.