Detection of ABO Discrepancy in a Case of Coronary Artery Disease by Conventional Tube Technique: A Miss by Column Agglutination Technology.

ABO and Rh blood grouping of donors and recipients is the first and foremost step in pretransfusion compatibility testing. Conventional tube technique (CTT) is used to test for blood grouping and Rh D typing. But the procedure is cumbersome, and there may be subjective variation during the interpretation of the test results. The other disadvantage is that it is not adaptable to automation. Many newer techniques, such as the column agglutination technique (CAT) used for pretransfusion testing, are amenable to automation. It is being preferred to shift from CTT to semiautomated or fully automated CAT platforms or other newer technologies in many blood centers. The CAT has the added advantage of increased sensitivity and stable end-point results. The results in automated platforms using CAT are equally efficient and reliable as CTT. However, sometimes it is noted that CAT misses subgroups detection. Here, we report a case with a subgroup of A that was failed to be detected by the CAT using dextran acrylamide gel, signifying the use of CTT in evaluating blood group discrepancy.