Direct Antiglobulin Test (DAT)

This Medical Laboratory Science lesson in Blood Bank supports laboratory science learning and laboratory interpretation for medical laboratory students and professionals.

Interpret the direct antiglobulin test as a detector of in vivo red-cell coating by IgG or complement, distinguishing polyspecific from monospecific reagent use in hemolysis, HDFN, and transfusion-reaction workups.

Intermediate32 min read15 sectionsBlood Bank
Section 1 of 150%

Learning Objectives

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Section 1 of 15

Learning Objectives

Learning Objectives

Section: Learning Objectives

Each objective below describes a competency you will apply at the immunohematology bench, practical laboratory reasoning first, memorization second.

  • Explain that the DAT detects red-cell coating that has already occurred in vivo, in contrast to tests that create sensitization in vitro
  • Differentiate polyspecific AHG reagent (detects IgG and/or complement) from monospecific anti-IgG and anti-C3d reagents and describe when each is used
  • Interpret a positive DAT within its clinical context (hemolysis, HDFN, transfusion reaction workup) without assuming it automatically halts transfusion