Antihuman Globulin Test Flashcards
other term for AHG test
Coomb’s test
how is it discovered
inject human serum into rabbits
developed by
Coombs and coworkers
color of AHG reagent
Green
types of AHG reagents
Polyspecific
Monospecific
type of AHG reagent that contains both anti-IgG and anti-C3d
Polyspecific
type of AHG reagent that contains either anti-IgG oranti-C3d
Monospecific
two types of AHG tests
Direct Antiglobulin Test (DAT)
Indirect antiglobulin test (IAT)
Detects in vivo sensitization of RBCs
DAT
detects in vitro sensitization of RBCs
IAT
Positive result for DAT
Visible agglutination
Positive result for IAT
Visible agglutination
difference of IAT from DAT
IAT requires incubation
percent of RCS used
2 - 5%
DAT Specimen
EDTA whole blood
DAT is for detection of
HDN
HTN
AIHA
IAT is for detection of
Antibody screening and identification
Antibody titration
RBC phenotyping
Weak D testing
Sources of error in AHG Tests (False-Positive)
improper specimen (ref or clotted)
overcentrifugation
bacterial contam
dirty glassware
Sources of error in AHG Tests (False-Negative)
Inadequate or improper washong of cells
undercentrifugation
serum:cell ratio not ideal
AHG reagent not added
what to do to prevent NEUTRALIZATION
RBCs must be saline-washed at least 3 times before adding AHG
Coombs control cells are
O positive RBCs coated with anti-D
TRUE/FALSE
Antiglobulin test reports NEGATIVE instantly
FALSE
*requires checking by use of Coombs control cells
