A report on a modified protocol for flow cytometry-based assessment of blood group erythrocyte antigens potentially suitable for analysis of weak ABO subgroups.

The RBC-FC analysis described here allows the detection of AB antigens weakly expressed in RBCs while achieving minimum background noise levels in negative control samples. Overall, the modified protocol provides a quick and reliable assay valuable in transfusion medicine and is potentially applicable to the characterization of rare weak ABO variants.