TOPIC 3 - P3 Flashcards
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Improper specimen (refrigerated, clotted) may cause in vitro complement attachment.
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ overcentrifugation and overreading
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ centrifugation after the incubation phase when PEG or other positively polymers are used as an enhancement medium
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Bacterial contamination of cells or saline used in washing
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Dirty glassware
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Presence of fibrin in the test tube may mimic agglutination
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Cells with a positive DAT will yield a positive IAT
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Polyagglutinable cells
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Saline contaminated by heavy metals or colloidal silica
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ using a serum sample for a DAT (use EDTA, ACD or CPD anticoagulated blood)
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Samples collected in gel separator tubes may have unauthentic complement attachment
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Complement attachment when specimens are collected from infusion lines infusing dextrose solutions.
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Preservative-dependent antibody directed against reagents
False-positive
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Inadequate or improper washing of cells
False-negative
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Failure to wash additional times when increased serum volumes are used
False-negative
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Contamination of AHG by extraneous protein (i.e., glove, wrong dropper)
False-negative
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ High concentration of IgG paraproteins in test serum
False-negative
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Early dissociation of bound IgG from RBCs due to interruption in testing
False-negative
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ Early dissociation of bound IgG from RBCs due to improper testing temperature (i.e, saline or AHG too cold or hot)
False-negative
(SOURCES OF ERROR IN ANTIHUMAN GLOBULIN TESTING)
DETERMINE IF FALSE-POSITIVE OR FALSE-NEGATIVE…
✓ AHG reagent nonreactive because of deterioration or neutralization (improper reagent storage)
False-negative