FIG. 3.
Comparison of blood group I antigen on the surface of native and sialidase-treated animal erythrocytes by FACS analysis. Human anti-I serum was used for the detection of blood group I antigen. Native and sialidase-treated erythrocytes from humans, cows, guinea pigs, and horses were fixed and incubated with human anti-I serum. As a control, biotin-labeled R. communis agglutinin (RCA) was used for the detection of ubiquitous glycans on the erythrocytes. As a negative control, fixed erythrocytes were incubated without anti-I serum and R. communis agglutinin. The erythrocytes were washed with PBS and incubated with the FITC-conjugated F(ab′)2 fragment of rabbit anti-human IgM antibody or FITC-conjugated streptavidin. The fluorescence intensities of the cells were analyzed. The white, gray, and solid portions of each histogram indicate results obtained with negative control cells, intact cells, and sialidase-treated cells, respectively.