direct antibody Test
Looks for the presence of IgG and/or complement on the RBCs. This causes hemolysis and can be due to an autoimmune disease, transfusion reaction, etc.
Indirect antibody Test
This is used when cross-matching people for a blood transfusion. It tests patients for the presence of unexpected alloantibodies (anti-D, anti-E, anti-C, anti-Kell, anti-Duffy). This is just a screen, if it is positive, you can then test for specific antibodies and then only transfuse blood that is negative for those specific antigens.
* 19/06/2013 Please excuse the doodle for saying “agglutination” though it is testing by agglutinating, the “A” in DAT stands for antibody. Thanks Robina for pointing this out!
Very good depiction of the DAT and IAT . One comment is that I believe Coombs reagent is an IgG rather than an IgM, since you have to attach the antibody at 37C. But I could be wrong. Thank you
Hi, the A in DAT and IAT (it’s not called IDAT) actually stands for ANTIGLOBULIN (not agglutination)
Thanks! You are totally correct!