Direct Antiglobulin Test (DAT) /Coombs test, direct

Preferred Specimen(s) 5 mL EDTA (lavender-top) whole blood or ACD-A or ACD-B (yellow-top) tube

Instructions If submitted with a CBC, HBA1c or any other test requiring a lavender-top tube, please submit a separate tube for this test

Transport Container EDTA (lavender-top) tube or ACD-A or ACD-B (yellowtop) tube

Transport Temperature Room temperature

Reject Criteria

  • Gross hemolysis
  • Serum separator tube (SST®)
  • Received frozen
  • Red-top tube

Methodology Immune Agglutination

Clinical Significance 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.