The Coomb’s test is an immunohematology assay used to detect antibodies against RBCs.

Indirect Coomb’s Test (ICT):

Identifies antibodies present in the patient’s serum that can react with RBC antigens.

Commonly used in cross‑matching blood before transfusion.

Helps detect alloantibodies in pregnant women that may cause hemolytic disease of the newborn (HDN).

Clinical uses include:

Ensuring safe blood transfusions.

Detecting maternal antibodies against fetal RBCs (Rh incompatibility).

Supporting diagnosis of immune‑mediated hemolysis.

Often performed alongside the Direct Coomb’s Test (DCT) for a complete evaluation.

Analyte: Free antibodies in serum that target RBC antigens.

Normal Result: Negative (no antibodies detected).

Abnormal Findings:

Positive ICT: Indicates presence of alloantibodies in serum, risk of transfusion reaction, or maternal antibodies against fetal RBCs.

Clinical Use:

Provides a screening tool for transfusion compatibility.

Detects immune‑mediated destruction of RBCs.

Supports prenatal care in Rh‑negative mothers.