The Ability of Trypsin to Restore Specific Agglutinating Capacity of Erythrocytes Treated with Periodate

Abstract

Treatment of human erythrocytes—group O, CD (Rh) positive, or group O, S positive—with dilute saline solutions of periodic acid at varying concentrations and pH, for varying periods of time, will diminish or abolish the capacity of these cells to agglutinate in the presence of the specific anti-serum (saline-agglutinating anti-D or anti-S). Subsequent exposure of aliquots of these periodate-treated cells to buffered solutions of crystalline trypsin restores this specific agglutinating ability. If cells are first trypsinated and then periodated, the loss of agglutinating properties is somewhat slower and less marked than when previously untreated cells are periodated. The specificity of these changes is shown by the lack of agglutination of negative control cells, similarly treated, and by the results of the absorption tests. This restoration of agglutination is presumed to occur by the action of trypsin in unmasking previously unavailable erythrocyte antigen sites.