Which test is commonly used to evaluate blood compatibility?

The direct Coombs test is a key laboratory test used to evaluate blood compatibility, particularly in the context of blood transfusions and hemolytic anemias. This test detects the presence of antibodies bound to the surface of red blood cells. In blood compatibility testing, it is critical to ensure that the recipient's immune system does not react against the donor's red blood cells, which can lead to transfusion reactions.

When performing this test, patient serum is mixed with red blood cells that are known to have specific antigens. If antibodies are present in the serum, they will bind to these cells and, upon the addition of a specific anti-human globulin reagent, cause agglutination (clumping) of the red blood cells, thereby confirming the presence of these antibodies. This process is vital for determining if a transfusion will be compatible, as the presence of antibodies can indicate a risk of hemolytic reactions.

In contrast, the other tests listed serve different purposes: the Rituximab test is typically used for monitoring therapy in certain conditions like lymphoma, hemoglobin electrophoresis is used primarily to identify and characterize different hemoglobin variants, and ELISA is a broad assay technique used to detect and quantify proteins, not specifically related to