Isolation and partial characterization of I antigen from I adult erythrocyte membranes.

: The i-active substance was isolated from i adult and I int erythrocyte membranes by butanol-water extraction and was purified by SDS-gel filtration and thin layer chromatography of peracetylated samples. The i-active substances from both types of erythrocytes showed also IF activity. In antigen isolated from i adult red cells the IF activity was lower than i activity. On the other hand, the antigen of I int red cells showed higher IF than i activity. The chemical characterization of isolated antigens indicated their glycosphingolipid character.