EDTA glycine acid treatment of red blood cells

IgG dissociation is necessary when a sample is direct antiglobulin test (DAT) positive and antigen testing using blood grouping serum reactive by the antiglobulin test is performed. Exposure of IgG-coated red blood cells (RBCs) to a low pH of 3.0 with EDTA glycine acid successfully dissociates the IgG, rendering the RBCs DAT negative 82 to 85 percent of the time. The procedure takes one minute or less and leaves RBC antigens intact and able to be typed except for those antigens in the Kell blood group system and for the high-prevalence antigen Er^a. Immunohematology2012;28:95–6.