Coombs Principle

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

Understand how antihuman globulin bridges IgG-sensitized red cells to produce visible agglutination, and how the direct and indirect antiglobulin tests apply that bridge in vivo and in vitro.

Intermediate26 min read15 sectionsBlood Bank
Section 1 of 150%

Learning Objectives

Getting started

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 how antihuman globulin (AHG) bridges IgG-sensitized red cells to produce visible agglutination
  • Differentiate the direct antiglobulin test (DAT, detects in vivo sensitization) from the indirect antiglobulin test (IAT, detects in vitro sensitization)
  • Interpret check-cell (Coombs control) results to confirm that a negative antiglobulin test is valid rather than a technical failure