Antihuman Globulin Test

Question 1

other term for AHG test

Answer 1

Coomb’s test

Question 2

how is it discovered

Answer 2

inject human serum into rabbits

Question 3

developed by

Answer 3

Coombs and coworkers

Question 4

color of AHG reagent

Answer 4

Green

Question 5

types of AHG reagents

Answer 5

Polyspecific

Monospecific

Question 6

type of AHG reagent that contains both anti-IgG and anti-C3d

Answer 6

Polyspecific

Question 7

type of AHG reagent that contains either anti-IgG oranti-C3d

Answer 7

Monospecific

Question 8

two types of AHG tests

Answer 8

Direct Antiglobulin Test (DAT)

Indirect antiglobulin test (IAT)

Question 9

Detects in vivo sensitization of RBCs

Answer 9

DAT

Question 10

detects in vitro sensitization of RBCs

Answer 10

IAT

Question 11

Positive result for DAT

Answer 11

Visible agglutination

Question 12

Positive result for IAT

Answer 12

Visible agglutination

Question 13

difference of IAT from DAT

Answer 13

IAT requires incubation

Question 14

percent of RCS used

Answer 14

2 - 5%

Question 15

DAT Specimen

Answer 15

EDTA whole blood

Question 16

DAT is for detection of

Answer 16

HDN
HTN
AIHA

Question 17

IAT is for detection of

Answer 17

Antibody screening and identification
Antibody titration
RBC phenotyping
Weak D testing

Question 18

Sources of error in AHG Tests (False-Positive)

Answer 18

improper specimen (ref or clotted)
overcentrifugation
bacterial contam
dirty glassware

Question 19

Sources of error in AHG Tests (False-Negative)

Answer 19

Inadequate or improper washong of cells
undercentrifugation
serum:cell ratio not ideal
AHG reagent not added

Question 20

what to do to prevent NEUTRALIZATION

Answer 20

RBCs must be saline-washed at least 3 times before adding AHG

Question 21

Coombs control cells are

Answer 21

O positive RBCs coated with anti-D

Question 22

TRUE/FALSE

Antiglobulin test reports NEGATIVE instantly

Answer 22

FALSE

*requires checking by use of Coombs control cells