One Step Strep A Rapid Test Cassette (Throat Swab)
Cat. No.: RH0507I
A rapid test for the qualitative detection of Strep A antigen in
throat swab specimens. For professional in vitro diagnostic use
The Strep A Rapid Test Cassette (Throat Swab) is a rapid
chromatographic immunoassay for the qualitative detection of Strep
A antigen from throat swab specimens to aid in the diagnosis of
Group A Streptococcal infection.
Streptococcus pyogenes is non-motile gram-positive cocci, which
contains the Lancefield group A antigen that can cause serious
infections such as pharyngitis, respiratory infection, impetigo,
endocarditis, meningitis, puerperal sepsis, and arthritis.1 Left
untreated, these infections can lead to serious complications,
including rheumatic fever and peritonsillar abscess.2 Traditional
identification procedures for Group A Streptococci infection
involve the isolation and identification of viable organisms using
techniques that require 24 to 48 hours or longer.3,4
The Strep A Rapid Test Cassette (Throat Swab) is a rapid test to
qualitatively detect the presence of Strep A antigen in throat swab
specimens, providing results within 5 minutes. The test utilizes
antibodies specific for whole cell Lancefield Group A Streptococcus
to selectively detect Strep A antigen in a throat swab specimen.
The Strep A Rapid Test Cassette (Throat Swab) is a qualitative,
lateral flow immunoassay for the detection of Strep A carbohydrate
antigen in a throat swab. In this test, antibody specific to Strep
A carbohydrate antigen is coated on the test line region of the
test. After the test strip is immersed into a specimen, the
extracted throat swab specimen reacts with an antibody to Strep A
that is coated onto particles. This mixture migrates up the
membrane to react with the antibody to Strep A on the membrane and
generate a colored line in the test line region. The presence of
this colored line in the test line region indicates a positive
result, while its absence indicates a negative result. To serve as
a procedural control, a colored line will always appear at the
control line region, indicating that proper volume of specimen has
been added and membrane wicking has occurred.
Strep A Reagent A (2M Sodium Nitrite)
Strep A Reagent B (0.4M Acetic Acid)
Materials Required But Not Provided
- For professional in vitro diagnostic use only. Do not use after
- Do not eat, drink or smoke in the area where the specimens and kits
- Handle all specimens as if they contain infectious agents. Observe
established precautions against microbiological hazards throughout
the procedure and follow the standard procedures for proper
disposal of specimens.
- Wear protective clothing such as laboratory coats, disposable
gloves and eye protection when specimens are assayed.
- Humidity and temperature can adversely affect results.
- Do not use test if pouch is damaged.
- Reagent B contains an acidic solution. If the solution contacts the
skin or eye, flush with large volumes of water.
- The positive and negative controls contain sodium azide (NaN3) as a
- Do not interchange reagent bottle caps.
- Do not interchange external control solution bottle caps.
STORAGE AND STABILITY
Store as packaged in the sealed pouch at room temperature or
refrigerated (2-30°C). The test strip is stable through the
expiration date printed on the sealed pouch. The test strip must
remain in the sealed pouch until use. DO NOT FREEZE. Do not use
after the expiration date.
SPECIMEN COLLECTION AND PREPARATION
- Only use reagents and sterile swabs provided in the kit.
- Collect the throat swab specimen with the sterile swab that is
provided in the kit. Swab the posterior pharynx, tonsils and other
inflamed areas. Avoid touching the tongue, cheeks and teeth with
- Testing should be performed immediately after the specimens have
been collected. Swab specimens may be stored in a clean, dry
plastic tube for up to 8 hours at room temperature or 72 hours at
2‑8°C. Transport swabs containing modified Stuart’s or Amies
medium?can also be used with this product.
- If a culture is desired, lightly roll the swab tip onto a Group A
selective (GAS) blood agar plate before using the swab with the
Strep A Rapid Test Cassette (Throat Swab).
DIRECTIONS FOR USE
Allow the test device, specimen, reagents, and/or controls to reach
room temperature (15-30°C) prior to testing.
1. Remove the test device from the sealed foil pouch and use it as
soon as possible. Best results will be obtained if the test is
performed immediately after opening the foil pouch.
2. Hold the Reagent A bottle vertically and add 4 full drops (approximately 240 uL) of Reagent A to an extraction test tube. Reagent A is red in
color. Hold the Reagent B bottle vertically and add 4 full drops (approximately 160 uL) of Reagent B. Reagent B is colorless. Mix the solution by gently
swirling the extraction test tube. The addition of Reagent B to
Reagent A changes the color of the solution from red to yellow.
3. Immediately add the throat swab into the extraction test tube of
yellow solution. Agitate the swab by rotating it at least 10 times. Leave the swab in the extraction test tube for 1 minute. Then express the liquid from the swab head by rolling the swab
against the inside of the tube and squeezing the tube as the swab
is withdrawn. Discard the swab.
4. Fit the dropper tip on top of the extraction test tube. Place
the test device on a clean and level surface. Add 3 full drops of
solution (approx. 100 μL) to the specimen well (S) and then start
5. Wait for the colored line(s) to appear. Read the result at 5
minutes. Do not read the result after 10 minutes...
INTERPRETATION OF RESULTS (Please refer to the illustration above)
POSITIVE: Two lines appear. One colored line should be in the control line
region (C) and another apparent colored line should be in the test
line region (T). A positive result indicates that Strep A antigen
is detected in the specimen.
NEGATIVE: One colored line appears in the control line region (C). No line
appears in the test line region (T). A negative result indicates
that Strep A antigen is not present in the specimen, or is present
below the detectable level of the test. The patient’s specimen
should be cultured to confirm the absence of Strep A infection. If
clinical symptoms are not consistent with results, obtain another
specimen for culture.
INVALID: Control band fails to appear. Results from any test which has not
produced a control band at the specified reading time must be
discarded. Please review the procedure and repeat with a new test.
If the problem persists, discontinue using the kit immediately and
contact your local distributor.
NOTE: 1. The intensity of the color in the test line region (T) will
vary depending on the concentration of Strep A antigen present in
the specimen. Therefore, any shade of color in the test line region
(T) should be considered positive.
2. Insufficient specimen volume, incorrect operation procedure, or
performing expired tests are the most likely reasons for control
Internal Quality Control
Internal procedural controls are included in the test. A colored
line appearing in the control line region (C) is an internal
positive procedural control. It confirms sufficient specimen
volume, adequate membrane wicking and correct procedural technique.
External Quality Control
In addition to your laboratory’s standard quality control
procedures, it is recommended that a positive and negative external
control be tested at least once within each test kit and by each
operator performing testing within a kit. This will verify that the
reagents and test strips are working properly and the operator is
able to correctly perform the test procedure. External positive and
negative controls are supplied in the kit.
Procedure for External Quality Control Testing
1. Add 4 full drops of Reagent A and 4 full drops of Reagent B into
an extraction test tube. Mix the solution by gently swirling the
2. Add 1 full drop of positive or negative control solution into
the extraction tube, holding the bottle vertically.
3. Place a clean swab into this extraction tube and agitate the
swab in the solution by rotating it at least 10 times. Leave the
swab in the extraction tube for 1 minute. Then express the liquid
from the swab head by rolling the swab against the inside of the
extraction tube and squeezing the extraction tube as the swab is
withdrawn. Discard the swab.
4. Continue with Step 4 of Directions For Use.If the controls do
not yield the expected results, do not use the test results. Repeat
the test or contact your distributor.
1. The Strep A Rapid Test Cassette (Throat Swab) is for in vitro
diagnostic use only. The test should be used for the detection of
Strep A antigen in throat swab specimens only. Neither the
quantitative value nor the rate of increase in Strep A antigen
concentration can be determined by this qualitative test.
2. This test will only indicate the presence of Strep A antigen in
the specimen from both viable and non-viable Group A Streptococcus
3. A negative result must be confirmed by culture. A negative
result may be obtained if the concentration of the Strep A antigen
present in the throat swab is not adequate or is below the
detectable level of the test.
4. The sterile swabs provided with this test must be used for
specimen collection. Other swabs have not been validated with this
5. Excess blood or mucus on the swab specimen may interfere with
test performance and may yield a false positive result. Avoid
touching the tongue, cheeks, and teeth5 and any bleeding areas of
the mouth with the swab when collecting specimens.
6. As with all diagnostic tests, all results must be interpreted
together with other clinical information available to the
Approximately 15% of pharyngitis in children ages 3 months to 5
years is caused by Group A beta-hemolytic Streptococcus. In
school-aged children and adults, the incidence of Strep throat
infection is about 40%. This disease usually occurs in the winter
and early spring in temperate climates.
Table: Strep A Rapid Test vs. PCR Test
|Strep A Rapid Test||Results||Positive||Negative|
Relative Sensitivity: 94% (88%‐98%)* Relative Specificity: 98%
Accuracy: 97% (96%‐98%)* * 95% Confidence Intervals
The following organisms were tested at 1.0 x 107 organisms per test and were all found to be negative when tested
with the Strep A Rapid Test Cassette (Throat Swab). No
mucoid-producing strains were tested.
|Group B Streptococcus||Bordetella pertussis||Corynebacterium diphtheria|
|Neisseria meningitidis||Streptococcus mutans||Streptococcus sanguis|
|Serratia marcescens||Group C Streptococcus||Hemophilus influenza|
|Group F Streptococcus||Neisseria gonorrhea||Candida albicans|
|Neisseria sicca||Staphylococcus aureus||Enterococcus faecalis|
|Klebsiella pneumoniae||Group G Streptococcus||Pseudomonas aeruginosa|
|Streptococcus pneumoniae||Neisseria subflava||Staphylococcus epidermidis|
Three physicians’ offices were used to conduct an evaluation of the
Strep A Rapid Test Cassette (Throat Swab). Personnel with various
educational backgrounds performed the testing. Each physician’s
office tested a randomly coded panel of samples consisting of
negative (20), low positive (20), and medium positive (20)
specimens for three days. The results obtained had a 96%
correlation with the expected results.
1. Murray, P.R., et al. Manual of Clinical Microbiology, 6th
Edition, ASM Press, Washington D.C. p.?299-307.
2. Webb, KH. Does Culture Confirmation of High-sensitivity Rapid
Streptococcal Tests Make Sense? A Medical Decision Analysis.
Pediatrics (Feb 1998), 101:2, 2.
3. Bisno AL, Gerber MA, Gwaltney JM, Kaplan EL, Schwartz RH.
Diagnosis and Management of Group A Streptococcal Pharyngitis.
Clinical Infectious Diseases (1997), 25: 574-83.
4. Needham CA, McPherson KA, Webb KH. Streptococcal Pharyngitis:
Impact of a High-sensitivity Antigen Test on Physician Outcome.
Journal of Clinical Microbiology (Dec 1998), 36: 3468-3473.
5. Shea, Y.R., Specimen Collection and Transport, Clinical
Microbiology Procedures Handbook, Isenberg, H.D., American Society
of Microbiology, Washington D.C., 1.1.1-1.1.30, 1992.
6. Nussinovitch, M, Finkelstein Y, Amir J, Varsano, I. Group A
beta-hemolytic streptococcal pharyngitis in preschool children aged
3 months to to 5 years. Clinical Pediatrics (June 1999),
Woods WA, Carter CT, Stack M, Connors Jr AF, Schlager TA. Group A
Streptococcal Pharyngitis in Adults 30 to 65 years of age. Southern
Medical Journal (May 1999), 491-492.7.
Span Biotech Ltd. is a research based company for rapid tests, with
strong support from National Key Laboratory of Technology Projects
of 10th and 11th Five-Year Plan and Faculty of Life Sciences of HuBei University.
SpanBio also housed a R&D team that is developing gene
recombination, cell cultivation and protein purification
techniques. SpanBio pays strict attention on rapid tests for human
being, animal diseases and food safety detection. It provides a
number of customized services to professional distributors and
partnering affiliates with excellent quality, competitive prices
and super service.
- Always best of all and always pay attention to innovation.
- Special customized service tightly following customers’ requests.
- Integrated excellent quality, competitive prices and super service
Span Biotech Ltd.
Add: 6A, Unit 5, Building 3, Sunshine Aloha, Bantian Industrial Park, Banxuegang Road , Longgang Shenzhen 518129