Why HBsAg result gets Negative in Rapid Test,
but Positive in ELISA or others test ?
In rapid test, the method uses monoclonal
antibodies. Conjugated to colloidal gold and polyclonal antibodies
immunobilized on a nitrocellulose strip in a thin line. The test sample
introduced flows laterally through an absorbent pad where it mixes with the
signal reagent. If the sample contains HBsAg, the colloidal antibody conjugate
binds to the antigen, forming an antigen-antibody colloidal complex. The
complex then migrates through the nitro cellulose strip by capillary action.
When the complex meets the line of immobilized antibody
colloidal complex, this forms a band indicating the sample is positive for
HBsAg. To serve as a procedural control, an additional line of antimouse
antibody has been immobilized at a distance above the test line on the strip.
It can detect HBsAg of all eleven subtypes in concentrations of 0.5 ng/ml in 20
minutes.
HBs Ag is a rapid
immuno-chromatographic test for the qualitative detection of Hepatitis B
surface Antigen in human serum, plasma or whole blood. It can be used for
prenatal or transfusional screening, and during acute infection or chronic
carriage of the hepatitis B virus. Early detection of infection is essential
for rapid initiation of adequate treatment.
Corresponded
by: cokku
