ICON DS Strep A is a rapid immunochromatographic assay for the qualitative detection of Group A Strep antigen directly from a throat swab specimen.
ICON DS Strep A is a simple, easy-to-use CLIA-waived dipstick format test. With outstanding performance, even in low colony count samples, ICON DS Strep A leaves little chance for misdiagnosis, minimizing the chance of rheumatic fever or over-prescription of antibiotics. In as little as five minutes, you will have accurate results so you can begin your patient’s treatment immediately and confidently.
ICON DS Strep A Brochure (Requires Adobe® Acrobat® Reader)
Frequently Asked Questions (FAQs)
Specimen
Q: What kind of swab should be used to collect a throat
swab specimen?
A: Collect throat swab specimens following standard clinical
procedures, using the sterile swabs supplied with this kit.
Q: How should specimens be collected?
A: Collect throat swabs specimens following standard clinical
procedures, using the sterile rayon swabs supplied in this kit.
Care should be taken in collecting the throat swab specimens to
avoid touching sides of the mouth and sampling inflamed or
exudative areas. Presence of excess amount of saliva or blood in
the collected sample can interfere with test results.
Q: Can specimens be stored prior to testing?
A: Swabs should be processed within 4 hours after collection,
unless they are stored in a refrigerator (2-8° C). If stored in
a refrigerator, swabs should be processed within 24 hours from
collection.
Q: Will transport media affect the test?
A: Swabs transported in liquid media prior to testing may result in
reduced sensitivity due to dilution of organisms.
Test Detection
Q: What part of the Strep A antigen molecule is
detected?
A: The carbohydrate portion of the antigen is detected.
Q: What is the antigen detection level of the
test?
A: The test is able to detect at least 1.5 x 105 CFU/mL.
Q: Is there any “hook” effect? If so, at what
level of Strep A organisms / antigen? If not, what is the highest
level of Strep A tested?
A: No “hook effect” has been observed up to 1 x 108
CFU/mL.
Q: A patient completed antibiotic treatment for Strep
throat and was then re-tested with the ICON® DS
Strep A Rapid Test Strip and culture. The rapid test result was
still positive, while the culture result was negative.
Why?
A: The ICON® DS Strep A Rapid Test Strip can detect
non-viable and viable Strep A organisms. The test may therefore
detect organisms which cannot be demonstrated in culture.
Q: Can this test be used for culture
confirmation?
A: No, this test is not designed for culture confirmation and is
for the qualitative detection of Group A streptococcus antigen
directly from throat swab specimens.
Test Procedure
Q:Why is it important to hold the bottles vertically when
dispensing Reagent A & Reagent B into the extraction test tube,
as indicated in the package insert?
A: Holding the bottles vertically rather than tilted at an angle
ensures that the dispensed drops are of the correct volume. It
helps to obtain full drop size and avoid air bubbles during the
squeezing of the bottles.
Q: If the solution mixture does not change to pink when
Reagent B is added to Reagent A (yellow), can the solution be used
for the test anyway?
A: No. If the color change does not occur, the reagents may be
contaminated (because the bottle caps were interchanged) or the
incorrect number of drops was used. Try repeating the procedure
with a new extraction test tube and the correct number of drops (4
drops of Reagent A & 4 drops of Reagent B). The solution
mixture must turn pink for it to be used for a test.
Q: Are Reagent A & Reagent B lot-specific? In other
words, can the bottles of Reagent A & B from one kit be used
with test strips from another kit of a different lot
number?
A: Do not interchange materials from different product lots.
Q: How important is it to vigorously mix the solution, as
indicated in the package insert?
A: This is an important part of the extraction process. It is
critical in extracting any Strep A antigen that may be present on
the swab into the liquid solution that will be used for the test
strip.
Q: If the test is used before the test components reach
room temperature, is the result reliable?
A: No. The test components must be at room temperature (15-30 C)
before the test is performed.
Q: If the test strip was removed from the foil pouch and
dropped on the floor prior to using it, will it still
work?
A: If the test is intact and the exposed membrane in the
“reaction window” was not damaged, it can still be used
and expected to function properly.
Q: Liquid was inadvertently applied onto the
“reaction window” of the test. Will it still
work?
A: No. Addition of any type of liquid into any other location other
than the test’s designated sample port renders the test
invalid. Use a new test.
Q: How many tests is it possible to run at a
time?
A: It depends on the proficiency of the user. However, even in
experienced hands, we do not recommend running more than 5 tests at
a time.
Interpretation
Q: When the sample is added to the test, red/pink fluid can
be seen migrating up the membrane. Is this normal?
A: A pink background is normal as the sample flows up the test
strip and will not affect the test result. As long as it does not
interfere with the interpretation of the line(s), the background
can be disregarded.
Q: How does one know that the test has been performed
properly?
A: As an internal procedural control, a red line appearing in the
control (C) region confirms the application of sufficient sample
volume and the performance of correct procedural technique.
Q: A positive result is read when two distinct red lines
appear, one in the control region (C) and another in the test
region (T). Do the two lines need to be of the same
intensity?
A: No. The intensity of the red color in the test line region (T)
will vary. Any shade of a red line in the test (T) region (darker
than, the same color as, or lighter than the control line) along
with a red line in the control (C) region is considered a positive
result.
Q: Will a positive result stay positive on the
test?
A: Read the result in 5 minutes but no later than 10 minutes after
the test strip has been dipped in the extracted solution.
Q: Can the result be read before the specified read
time?
A: No. Even though a positive result may appear earlier, it is
important that the test be allowed to fully develop for 5
minutes.
Q: Q: Can the result be read after the specified read
time?
A: The test result is read no later than 10 minutes after the test
strip has been dipped in the extracted solution
Storage
Q: How should the test kits be stored?
A: Store the tests as packaged in their sealed pouch at 2 to
30° C until use. Do not freeze the tests. If stored
refrigerated (2 to 8°C), allow the test devices to equilibrate
to room temperature (15 to 30°C) prior to use.
Q: If the foil pouch has been opened, should the test be
used right away?
A: Because humidity in the air can affect the integrity of the
test, it is recommended that the test be used immediately once the
foil pouch has been opened. If a pouch is found to be punctured or
have a broken seal, do not use the test inside. (FYI ONLY –
Devices are stable for up to 1 hour after pouch has been opened per
PBM).
Q: Can the test be used beyond the expiration date on the
foil pouch?
A: No. The test should not be used past its expiration date under
any circumstances.
Q: What is the shelf life?
A: Until the expiration date labeled on the test pouch (which is
the same as the one labeled on the kit box), when stored as
indicated in the product instructions. (On a need to know basis
– kit dating is 18 months from date of manufacture.)
