The purpose of testing with anti-A, B is to detect what?

Testing with anti-A and anti-B is primarily aimed at identifying the presence of different subgroups of the A blood group, particularly distinguishing the presence of A and its various subtypes. The anti-A reagent reacts with the A antigen, and variations in strength and type of the antigen can indicate the presence of subgroup A which may not be accurately detected with standard anti-A testing alone.

Subgroups of A, such as A3, Ax, Ay, and Am, can express different phenotypic characteristics that may not be picked up if only standard anti-A is used. Using anti-A and anti-B helps in confirming the presence of A antigens and differentiating the more common A1 from subgroups of A, which are significant in blood typing and transfusion practices.

In this context, testing with anti-A and anti-B serves to ensure that any variants of the A antigen are appropriately recognized, enhancing the accuracy of blood typing and ensuring compatibility in transfusions.