TestPack Strep A is a rapid immunoassay for the
qualitative detection of Group A Streptococcal (Group A Strep)
antigen in throat swab specimens from patients with suspected Group
A Streptococcal associated pharyngitis and for confirmation of
presumptive Streptococcus Group A colonies isolated on
culture plates.
The Streptococcal Group A specific antigen is extracted from the
throat swab using Reagent 1 and Reagent 2. Following this, Reagent
3 is added to neutralise the acid formed by Reagents 1 and 2.
The mixture is then added drop wise into the Sample Well of the
reaction disc and allowed to migrate through the membrane until it
reaches the End of Assay Window. As the specimen extract migrates
through the membrane, it mobilises the Group A Strep
antibody-coated colloid.
If Group A Streptococcal antigen is present in the specimen it will
form a complex with the antibody-colloid. The antibody colloid
complex migrates through the membrane and is then captured by the
Group A Strep antibody in the result window (Patient bar),
providing a visual indication of the presence of antigen.
The test can be read as soon as the End of Assay Window has changed
colour (turned pink/red) or 10 minutes after the addition of the
sample extract. A pink/red Plus Sign (+) appearing in the Result
Window indicates the presence of the Group A Strep antigen. A Minus
Sign (–) indicates no antigen was detected.
TestPack Strep A also provides the following
integral control features:
- Extraction reagents are colour coded to indicate that Reagents
1, 2, and 3 are added in the proper order.
- The plus/minus format provides an easy to interpret result for
positive and negative patient specimens.
- The appearance of a pink/red colour in the End of Assay Window
indicates that the test is complete.
- The appearance of the Positive On Board Control (POS CTL √) and
the Minus Sign (–) gives an extra measure of quality control by
demonstrating the functionality of the antibody-colloid complex and
capture antibody systems, since they will only appear if the
reagents are chemically active. The POS CTL (√) and the Minus Sign
(–) should always appear, for the test be valid.
- An additional Negative On Board Control (NEG CTL X) indicates
non-specific binding and invalidates the test.