IMMUNOCHEMICAL STUDIES ON BLOOD GROUPS : LIV. CLASSIFICATION OF ANTI-I AND ANTI-i SERA INTO GROUPS BASED ON REACTIVITY PATTERNS WITH VARIOUS ANTIGENS RELATED TO THE BLOOD GROUP A, B, H, LE(a) LE(b)AND PRECURSOR SUBSTANCES

Quantitative precipitin assays were carried out with eleven anti-I and five anti-i cold agglutinin sera. Their reaction patterns with precursor substances and with certain antigens related to the A, B, H, Le(a), and Le(b) substances revealed at least six types of I and four types of i specificity. All of the I and i determinants appear to be represented in varying amounts on that fraction of the ovarian cyst precursor substance OG which was precipitated by 20% ethanol (OG 20% 2X). Only some of these determinants can be detected in the first periodate oxidation stages of A, B, and H substances, in cow substances, and in hydatid cyst fluid.