A comparative study showing the potency of anti-C3d and anti-immunoglobulin G in polyspecific anti-human globulin using fresh and cryopreserved red blood cells.

Background: The antiglobulin test is used to determine red blood cells (RBCs) having surface-bound immunoglobulin G (IgG) and/or complement (C3b, C3d, C4b, and C4d) free in serum or attached to antigens on RBCs. In such circumstances, the quality of the anti-human globulin (AHG) which is used in routine cross-match/indirect agglutination test plays a vital role in blood transfusion medicine. For potency testing of polyspecific AHG, it is recommended by the Food and Drug Administration and the Centre for Biologics Evaluation and Research to use fresh O +ve RBCs within 1 hr of collection for sensitization with anti-C3d.