Saline–indirect antiglobulin test

A saline–indirect antiglobulin test (IAT) is performed without addition of enhancement media to increase the binding of antibody to the red blood cell antigen during the 37°C incubation. Although infrequently used as a primary means for antibody detection or identification, this test is useful because of the variety of possible applications in antibody identification studies. It is critical to the test sensitivity to allow enough incubation time (30–60 minutes) for maximum antibody binding to occur. The saline test can also be subject to a direct agglutination reading after immediate spin, room temperature, or incubation at 37°C before conversion to the IAT. This step allows further flexibility in assessing the reactivity of directly agglutinating allo- or autoantibodies in tests performed at 37°C or lower temperatures.