IP: The antibody MEM-57 immunoprecipitates from a detergent lysate of surface-radioiodinated T cells a strong zone of about 22 kDa and a weak 28-kDa zone, which is typical pattern yielded by a reference antibody Leu-4 (SK7), Flow Cytometry: 2 - 5 ug/ml; Positive Control: peripheral blood lymphocytes, JURKAT human leukemia T cell line.