PREFINAL LABORATORY L1: HBsAg TEST Flashcards
What type of assay is used in HBsAg test
immunochromatography assay
specimens where HBsAg can be detected
human serum, plasma, whole blood
name of the principle of HBsAg test
double antibody sandwich assay
what substances are dry-immobilized in the test device
colloidal gold conjugated anti-HBsAg antibody complexes
what happens to the sample when added to the test kit
migrates by capillary diffusion through the strip re-hydrating the gold complexes
according to the principle, what happens to the present HBsAg
react with gold conjugate complexes forming particles
the formed particles will continue to migrate until what zone
Test zone
the test zone contains what substances
anti-HBsAg antibodies
what happens to the formed particles if they reach the test zone
immobilized by anti-HBsAg antibodies, forming a red line
what happens to the gold conjugate if there are no HBsAg present
the gold conjugate will continue to migrate alone until the control zone
the control zone contains what substances
goat anti-mouse IgG antibody
what happens to the gold conjugate when it reaches the control zone
immobilized by goat anti-mouse IgG antibody, forming a red line
materials provided by the HBsAg test kit
1) QuickProfile HBsAg test
2) Instructions for use
3) Disposable transfer pipet
materials required but not provided
1) whole blood or plasma
2) serum
3) timer or clock
acceptable anticoagulants for plasma specimen in HBsAg testing
heparin or EDTA
storage temperature of sealed pouches of HBsAg test kit
4-30 C
T or F:
test kit must be used immediately after removed from test pouch
T
how to dispose HBsAg test specimens
autoclaving at 121C for at least 20 mins or treated with 0.5% sodium hypochlorite 1-2 hours before disposal
heat inactivation of spx may cause
hemolysis
protein denaturation
if specimens are to be stored, what should be done to avoid hemolysis
remove rbcs
what should be done if sample cannot be tested within 24 hours
serum or plasma must be frozen until the test can be performed
T or F:
not allowing the sample to reach room temperature will not cause any dicrepancies
F
should be allowed to reach room temperature prior to tetsing
what can be added as preservative in HBsAg specimens
sodium azide
percentage of sodium azide
up to 0.1%
catalog number of HBsAg test strip
71003
procedure for HBsAg test strip
1) bring all materials and specimens to room temperature
2) remove the test strip from the sealed foil pouch
3) label the specimen with specimen identity by writing the ID on the top label of the strip
4) place the test strip on a flat horizontal surface
5) use the transfer pipet to draw up the sample
6) hold the transfer pipet in a vertical position over the sample pad and dispense 2 drops of sample onto the sample pad
7) read the result after 20 mins after adding the sample
2 drops of sample is equivalent to how many microliters
80-100 uL
how many minutes should the result be read
20 minutes after adding the sample
catalog number of HBsAg test card
71004
procedure for HBsAg test card
1) bring all materials and specimens to room temperature
2) remove the test card from the sealed foil pouch
3) label the specimen with specimen identity by writing the ID area of the cassette
4) place the test card on a flat horizontal surface
5) use the transfer pipet to draw up the sample
6) hold the transfer pipet in a vertical position over the sample well and dispense 2 drops of sample onto the sample well
7) read the result after 20 mins after adding the sample
positive samples may show (positive/negative) results before 20 mins
positive
results after how many minutes may give inaccurate results
30 minutes
interpret: POSITIVE, NEGATIVE or INVALID
one colored band appears on C and T
POSITIVE
interpret: POSITIVE, NEGATIVE or INVALID
faint colored band only appears on T
INVALID
interpret: POSITIVE, NEGATIVE or INVALID
one band appears on C, faint colored band appears on T
POSITIVE
interpret: POSITIVE, NEGATIVE or INVALID
one colored band appears on C, none on T
NEGATIVE
interpret: POSITIVE, NEGATIVE or INVALID
no colored band appears on C and T
INVALID
what should be done if test is invalid
repeat test with a new device
limitations of HBsAg test kit
1) the test is for in vitro use only
2) negative results do not rule out the possibility of hepatitis b infection or exposure
3) positive results alone cannot be the final diagnosis of infection
4) test is only for testing of individual serum/plasma/whole blood. Do not use for testing other body fluids or pooled blood samples
5) only qualitative detection, does not indicate the quantity of antibodies
QuickProfile HBsAg test can detect HBsAg with how many concentration
1.0 ng/mL
sensitivity, specificity and accuracy of QuickProfile HBsAg test
99.6%
