Role of Calcium in Complement Dependent Hemolysis.

Abstract
Summary The cation requirements of two complement dependent hemolytic systems, one involving red cells from patients with paroxysmal nocturnal hemoglobinuria, and the other involving antibody coated sheep red cells, are similar when studied in undiluted human serum as a source of complement. Both are inhibited by the presence of Na3HEDTA, but not by Na2Mg EDTA. These results suggest that the need for Ca+ + in complement dependent hemolysis is not absolute, while the need for Mg++ is.