Changes in surface negative charge and agglutination kinetics in red blood cells

Abstract

Polylysine (pLys) agglutinates old red blood cells (RBC) at a higher rate than young ones. A gradual decrease in surface negative charge increases first the rate of agglutination due to lessen- ing of mutual repulsion. Further removal of surface charge results in decline of agglutinability because of insufficient binding sites for pLys. Two factors play a role in the agglutination by pLys: (1) the density of attachment sites; and (2) the mutual repulsion between cells.