the addition of mg2+ or ca2+ or of their chelators ( edta , egta ) to the extract-treated serum enhances or abolishes the lysis 2 - the reduction of complement acitvity in fresh serum incubated for 60 ' with pnh-extract 3 - the appearance of c3 breakdown products in serum incubated with pnh-extract , demonstrated by crossed immunoelectrophoresis .
C0009498
complement
C0229671
serum