Monoclonal anti-H antibody A46-B/B10 suited for differentiating blood groups A1 and A2 reveals also heterogeneity within blood group B.

A monoclonal antibody (mAb) recognizing H antigen was obtained from a BALB/c mouse immunized with MCF-7 (human mammary carcinoma) cells. This antibody (A46-B/B10, IgM) has been tested on a total of 753 blood samples. It strongly agglutinates human erythrocytes of blood groups 0, A2 and A2B, but not or only very weakly A1 and A1B. This mAb promises to be useful in the determination of A and AB subgroups in blood group serology. Evidence is presented that this antibody might also be able to define B subgroups. Among 263 B blood samples, 45 (17.1%) were negative or only weakly positive with A46-B/B10.