What does Coombs indirect mean?

Coombs indirect refers to the indirect Coombs test, a laboratory procedure used to detect antibodies against red blood cells in a patient's serum. This test is commonly employed in blood transfusion compatibility testing and in diagnosing hemolytic anemia or Rh incompatibility in pregnancy. By mixing the patient's serum with red blood cells of known antigenicity, the test identifies whether antibodies are present, which could lead to agglutination of the red blood cells.