THE RACIAL DISTRIBUTION OF ISOHEMAGGLUTININ GROUPS

Abstract

According to our present understanding of human isohemagglutinins, there exist in the blood two types of specific agglutinating substances, which may be designated a and b. In the red cells there are two specific types of agglutininogenic substances, which may be called A and B. The agglutinin of Type a will agglutinate only cells containing the agglutininogenic substance A, and Agglutinin b will agglutinate only cells containing Agglutininogen B. Obviously, one type of agglutinin will occur only in the absence of its corresponding agglutininogen, a fact utilized in classifying samples of blood. A given specimen of blood may contain either one of these specific agglutinins, or both, or neither. This distribution of agglutinins and agglutininogens makes it possible to divide all samples of human blood into four different groups. One group contains both types of specific agglutininogens, but the serum contains no agglutinins. A second group contains Agglutinin b and