Cells of the A3 subgroup commonly exhibit which reaction?

The A3 subgroup of the A blood group is known for its unique serological characteristics. One of the hallmark reactions of A3 subgroup cells is that they typically demonstrate a mixed-field reaction when tested with anti-A,B. This mixed-field reaction arises because A3 cells can produce a significant proportion of A antigen as well as other subgroups, leading to a population of cells that exhibit varying levels of reactivity.

When cells are mixed with anti-A,B serum, it can result in both agglutination of cells expressing the A antigen and non-agglutination of those that do not show the same level of antigen expression. Hence, the presentation of both reacted and unreacted cells leads to the mixed-field appearance.

In contrast, other reactions such as those with Dolichos biflorus, anti-A, or anti-H are not characteristic of the A3 subgroup. Dolichos biflorus specifically reacts with A1 and not necessarily with A3, while anti-A typically would react uniformly with A cells. Anti-H is typically seen in O blood types and does not specifically apply to the presence of A antigens in the A3 subgroup.