Comparative Studies on the Rates of Re‐Expression of Human Histocompatibility Antigens after Papain Treatment

Papain treatment was used to remove surface human histocompatibility antigens from the peripheral blood lymphocytes of one individual. The rates of re‐expression of two antigens, 4a and HL‐A12, were measured and compared to ascertain whether this might throw some light on the relationship between the two antigens. Possible implications are discussed. Lymphocytes, which had been previously stored in liquid nitrogen, were also shown to be capable of resynthesising antigen after papain treatment.