When performing manual ABO-RhD blood grouping, why do I have to use additional anti-A,B and anti-D reagent?

Question

I kind of understand why i need to do anti-D in duplicate(but please still explain if you know), but not really know why anti-A,B is needed too, i mean you can really tell the ABO group by just looking at the results of anti-A and anti-B alone????

My dear first answerer, i didn't say i can find out the blood group by just looking at anti-A or anti-B result, i did say i need both, the question is why an additional anti-A,B (a single polyclonal antibody that can bind to both A and B antigen) result is done in addition to anti-A and anti-B.

Answer 1

Anti-A,B is a separate antibody from the Anti-B formed in group A people and the anti-A formed in B people, and in some subgroups of either, particularly A (such as A 2, will react more strongly with anti-A,B.

Those cases are rare, so the major reason is for duplication, lessens error rate. Blood banking is designed to lessen error rates, as an error in the ABO group could easily be fatal.

Answer 2

Really? How?
You may be A, B, 0, or AB. You need both anti-A and anti-B