Using immunoelectron microscopy, the distribution of the H antigen sites
on human erythrocytes was observed in 40 samples of adult, newborn and fetal blood of
different ABO phenotypes. The attached ferritin particles indicating the H antigen sites
conspicuously varied in number from cell to cell in every specimen. The number of H
antigen sites per single red cell was estimated on an average for each sample as follows :
O, 3 x 10^5; B, 2 x 10^5; A(1), 1.5 x 10^5; A(1)B, 10^5; A2B, 1.5 x 10^5; Ax, 2.5 x10^5; AxB, 10^5;
Bm, 4 x 10^5 ; Bw(leukemia), 4 x 10^5; O(newborn), 2.5 x 10^5; B(newborn), 3 x 10^5; A(1)(newborn),
1.5 x 10^5; A(1)B(newborn), 2 x 10^5; A(1)B(fetus), 10^5.
The cells in each sample were divided into six cell-populations according to the number
of H antigen sites present. The ratios of distribution of such cell populations are compared
for all samples.