blood immunoglobulin amount blood immunoglobulin M amount The proportion, quantity, or volume in whole blood, serum, or plasma of this immunoglobulin formed during the early part of the immune response that is the most efficient antibody in stimulating complement activity. 2012-11-28T03:27:18Z EFO:0004993 VT:0010481 MP:0002494 immunoglobulin M measurement caripark EFO:0020466 Trait.ontology