Dec 31, 2023 · This is why the direct antiglobulin (Coombs) test (DAT) has different sensitivity levels, utilizing polyspecific AHG for broad detection and monospecific AHG for identifying specific antibody types. When the direct antiglobulin test (DAT) result is positive, the DAT test will be interpreted as "Invalid – See addl testing" and the polyspecific DAT test will be performed. Direct Coombs Test is used to demonstrate in-vivo coating (in-vivo sensitization) of red cells with antibodies or complement in particular, IgG and C3d. Washed red cells from a patient or donor are tested directly with antihuman globulin reagent (AHG). Feb 1, 2017 · The overall objective of our review is to provide practicing pathologists with a guide to identify situations when the DAT is useful and to highlight disease-specific shortcomings as well as general pitfalls of the test. Direct antiglobulin test with polyspecific antihuman globulin serum. Red cells found to be positive are further tested with monospecific antisera (anti-IgG and anticomplement). Feb 27, 2017 · Never fear, though, my friend Sue Johnson is a master teacher who has explained the essentials of the DAT to thousands of students! She is my guest on this episode to guide us to great clarity on this most excellent immunohematology test. Oct 14, 2025 · Based on the technique and objectives, there are two varieties of antiglobulin tests: the direct antiglobulin test (DAT)/direct Coomb's test (DCT), and the indirect antiglobulin test (IAT). Clinical Significance Direct Antiglobulin Test (DAT) - The DAT (Direct Coomb's test) is positive if red cells have been coated, in vivo, with immunoglobulin, complement, or both. A positive result can occur in immune-mediated red cell destruction, autoimmune hemolytic anemia, a transfusion reaction or in patients receiving certain drugs. DAT testing may be performed on automated analyzer or standard tube method using polyspecific DAT reagent. Further testing with DAT IgG

specific and Complement will be performed if reactivity noted with polyspecific DAT reagent. Sep 12, 2022 · Antiglobulin testing, also known as the Coombs test, is an immunology laboratory procedure used to detect the presence of antibodies against circulating red blood cells (RBCs) in the body, which induce hemolysis.