Lysis of sheep red cells in neat autologous serum as a source of antibody and complement.

: Lysis of autologous sheep red cells (labeled with methotrexate as the target hapten) by neat autologous serum was studied. The results indicated that the efficiency of lysis under physiological concentrations of cells and serum was about the same as lysis of the same target cells sensitized with autologous antibody and guinea pig serum as the source of complement. The data also indicate that the one-hit mechanism of immune lysis operates under near physiological conditions.