Blocking of anti-C15 (A) and anti-C9 (B) by immnunizing antigens. Km3 cell lysate was separated in 8% SDS-PAGE and electrophoretically transferred onto a nitrocellulose membrane. The blots were cut into strips and Western blotting was performed using various preparations of primary antibodies. (A) Lane 1, anti-C15 versus cell lysate; lane 2, preimmune IgG; lane 3, anti-C15 blocked by immunizing antigen; lane 4, anti-C15 blocked with GST. (B) Lane 1, anti-C9; lane 2, preimmune IgG; lane 3, anti-C9 blocked by immunizing antigen; lane 4, anti-C9 blocked by GST.