The anti-A and anti-B we use are monoclonal and extremely potent! They have no trouble directly and strongly agglutinating red cells of the appropriate type, so if you see a reaction that’s anything other than a 3+ or 4+ (very strong, in other words), something is not right! The reactions are almost always very strong.Tips and Tricks for Cell Grouping Interpretation: There are really only four patterns that are seen in the VAST majority of people being typed. Sadly, anti-B is not blue, because that would be really easy to remember, wouldn’t it? The outrage!!Īgain, the pattern of how the person’s cells react with those two antibodies determines the interpretation of the ABO group on the cell grouping test. Why? Practically, it is so the blood bank worker can glance at the tube and see whether or not the antibody was actually added. This test goes by several names, depending on whom you ask! Most blood bankers call it the “front-type,” but others call it “cell grouping” or “forward grouping.” Whatever you call it, this simple test gets you halfway to determining someone’s ABO type.Īlso, those preparing for standardized exams should note that, by convention in most of the world, the reagent (laboratory) anti-A is colored blue, while anti-B is colored yellow. Hey, don’t let anyone confuse you: There is no such thing as an “O” antigen, and neither do we use “anti-O” in our testing. We just separate the plasma and red cells from the person to be tested (by spinning the sample tube really fast), and then we mix the person’s red cells with really strong, laboratory-derived antibodies against the A antigen (“anti-A”) and the B antigen (“anti-B”). The first part of laboratory testing to determine someone’s ABO type just answers the question, “Does this person have A, B, both, or neither on their red cells?” This test is really straightforward, and few have trouble understanding it. The small number of people who have both enzymes will make both antigens, and those who lack both enzymes will make neither. In order to better understand our tests, you have to know a little bit about the antigens and antibodies that define someone’s ABO type.Ī person with the A transferase enzyme will make A antigen on their red blood cells (RBCs), while someone with the B transferase makes B. The ABO Blood Group System is clearly the most important system, since just about everything we do in blood banking revolves around ensuring that a donor and a recipient are either “ABO-compatible” (the definition varies somewhat by product, but in general, that means the recipient does not have an ABO antibody that would harm the transfused donor red blood cells) or “ABO-identical” (donor and recipient have exactly the same ABO type). This post will focus on the essentials of ABO testing so you can be better prepared for the cases Nicole will discuss in the podcast. If you want lots more detail on ABO than I can cover here, just watch that video from the 15:30 mark to 33:05. NOTE: In 2011, I published a video covering the basics of the blood groups, including ABO ( you can find it on the BBGuy video page). Nicole Draper takes us on a tour of the essentials of recognizing and dealing with ABO discrepancies. This post also serves as an introduction to episode 054 of the Blood Bank Guy Essentials Podcast.
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