A rapid method for the production of erythrocytes in the state "EC4" and "EC43"

The present report describes simple methods for preparing red blood cells coated with complement components. Erythrocytes coated strongly with C4 and C3 (EC43 cells) can be prepared using the standard sucrose hemolysis reaction system. Erythrocytes coated with C4 but not C3 (EC4 cells) can be prepared by a slight modification (addition of EDTA to sucrose prior to adding serum). Occasional sera (especially from black subjects) produced weak C3 coating of red blood cells in the modified sucrose hemolysis reaction. This C3 coating could be entirely abolished (without reducing C4 coating) by using Mg++ poor serum produced by dialyzing serum against Mg++ free barbital buffer. The EC43 and EC3 cells are extremely useful in analysis of anticomplement antiglobulin sera.