Positive direct antiglobulin test 2019-02-23T17:43:12Z The DAT is a method used to detect immunoglobulin or complement bound in vivo to RBCs, using anti-human reagents. There are 3 different reagents that may be used: monospecific reagents to detect either bound immunoglobulin G (IgG) or bound complement (C3) and polyspecific reagents that can simultaneously detect IgG and/or C3. In screening of RBCs for the presence of bound globulins and/or C3, many laboratories may choose to use the polyspecific reagent initially (ie, as a screen for any bound IgG and/or complement) and, if positive, subsequently use monospecific reagents to specifically distinguish what is bound to the RBC surface. A positive result of the direct antiglobulin test (DAT), a method of demonstrating the presence of antibody or complement bound to red blood cell (RBC) membranes by the use of anti-human globulin to form a visible agglutination reaction. Anti-erythrocyte autoantibody positivity