Negative surplus charge of coated erythrocytes

The effect on the net negative surface charge of single or multiple coating of erythrocytes was studied on human group A red cells previously washed and fixed. Single coating with either group A antiserum or protectin decreased the electrophoretic mobility of erythrocytes by 16% and 13%, respectively. Following an incubation in group A glycophorin or bovine submaxillary mucin of agglutinin coated cells, the electrophoretic mobility was restored or slightly increased compared with uncoated erythrocytes. Upon repeating this scheme, the second agglutinin binding again reduced these cells' cytophoretic mobility, and they were accelerated once more by a second coating with acid glycoprotein. Intensity and homogeneity of colloidal iron staining of uncoated and variously coated erythrocytes reflected their electrophoretic retardation and acceleration, respectively.