standard operating procedure for the direct antiglobulin test

Provincial Blood
Coordinating Program
Standard Operating Procedure For
Performing The Direct Antiglobulin
Test.
TITLE: Standard Operating Procedure for Performing the
Direct Antiglobulin Test
1.0 Principle
To detect in vivo sensitization of red blood cells (RBC) and to determine which
protein is coating red cells.
A 3% saline suspension of the red blood cells to be tested is washed with saline.
Antiglobulin reagents, polyspecific (anti-IgG and C3) and/or monospecific (anti-
IgG and anti-C3) antisera, are added to the washed red cell button, mixed,
centrifuged and then examined microscopically.
2.0 Scope and Related Policies
2.1 The facility shall develop and maintain operating procedures for each
activity that affects the safety of recipients.
2.2 The facility’s SOP manual shall be available to all staff at all times to cover
the activities they perform.
2.3 Quality control shall be carried out as specified in an operating procedure.
2.4 To provide work instruction for consistent testing, interpretation and
reporting of the Direct Antiglobulin Test (DAT).
2.5 The Direct Antiglobulin Test (DAT) may be performed for investigation of
• Hemolytic disease of the newborn
• Autoimmune hemolytic anemia
• Transfusion reactions
• Sensitization caused by drugs
2.6 A DAT is required if an auto control is not done in the antibody screen and:
• Antibody identification is required and an auto control cannot be done
(e.g. limited volume of plasma)
• Antigen typing of the patient cells is required
2.7 The antiglobulin reagent shall contain antibodies to IgG and C3d component
of complement. The only exception is cord blood testing that may be
performed with a monospecific anti-IgG reagent.
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This document may be incorporated into each Regional Policy/Procedure Manual.
NL09-005
Version: 2.0
Effective Date: 2011-02-14
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