CE Lateral Flow Immunochromatographic Assays Clostridium difficile
Toxin A+ Toxin B Combo Rapid Test Cassette
An IVD rapid test for the detection of Clostridium difficile Toxin
A and Toxin B antigens in human feces samples For professional use
The Clostridium difficile Toxin A+ Toxin B Combo Rapid Test Cassette (Feces) is a rapid
chromatographic immunoassay for the qualitative detection of
Clostridium difficile Toxin A and Toxin B antigens in the human
Clostridium difficile is an anaerobic bacteria acting as an opportunistic pathogen: it
grows in the intestine when the normal flora has been altered by
treatment with antibiotics.1,2,3 Toxinogenic strains of Clostridium difficile cause infections from
mild-diarrhea to pseudomembranous colitis, potentially leading to
Disease is caused by two toxins produced by toxinogenic strains of
C.difficile: Toxin A (tissue-damaging enterotoxin) and Toxin B
(cytotoxin). Some strains produce both toxins A and B, some others
produce Toxin B only. The potential role of a third (binary) toxin
in pathogenicity is still debated.4
How to use?
Allow the test, specimen, stool collection buffer and/or control to
equilibrate to room temperature (15-30°C) prior to testing.
SPECIMEN PREPARATION PROCEDURE:
- To collect fecal specimens:Collect sufficient quantity of feces
(1-2mL or 1-2g) in a clean, dry specimen collection container to
obtain enough antigens (if present).Best results will be obtained
if the assay is performed within 6 hours after collection. Specimen
collected may be stored for 3 days at 2-8°C if not tested within 6
hours. For long term storage, specimens should be kept below -20°C.
- To process fecal specimens:
- For Solid Specimens:Unscrew the cap of the specimen collection tube, then randomly stab the specimen collection applicator into the fecal specimen at least 3 different sites to collect approximately 50 mg of feces (equivalent to 1/4 of a pea). Do not scoop the fecal specimen.
- For Liquid Specimens:Hold the dropper vertically, aspirate fecal specimens, and then
transfer 2 drops of the liquid specimen (approximately 80 µL) into
the specimen collection tube containing the extraction buffer.
Tighten the cap onto the specimen collection tube, then shake the specimen collection tube vigorously to mix the specimen and the extraction buffer. Leave the
collection tube for reaction for 2 minutes.
3. Bring the pouch to room temperature before opening it. Remove
the test cassette from the 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.
4. Hold the specimen collection tube upright and unscrew the tip of the specimen collection tube. Invert the specimen collection
tube and transfer 3 full drops of the extracted specimen (approximately 120mL) to the specimen well (S) of the test
cassette, then start the timer. Avoid trapping air bubbles in the
specimen well (S). See illustration below.
5. Read the results at 10 minutes after dispensing the specimen. Do not read results after 20
6. Note: If the specimen does not migrate (presence of particles),
centrifuge the diluted sample contained in the extraction buffer
vial. Collect 120µL of supernatant, dispense into the specimen well
(S). Start the timer and continue from step 5 onwards in the above
instructions for use.
INTERPRETATION OF RESULTS
The results are to be interpreted as follows:
POSITIVE:*Two distinct colored 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
*NOTE: The intensity of the color in the test line region (T) will vary
depending on the concentration of Clostridium difficile antigen
present in the specimen. Therefore, any shade of color in the test
line region (T) should be considered positive.
NEGATIVE: One colored line appears in the control line region (C). No line appears in the test line region (T).
INVALID: Control line (C) fails to appear. Insufficient specimen volume or incorrect procedural techniques
are the most likely reasons for control line failure. Review the
procedure and repeat the test with a new test cassette. If the
problem persists, discontinue using the test kit immediately and
contact your local distributor.
An internal procedural control is 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.
Control standards are not supplied with this kit; however, it is
recommended that positive and negative controls be tested as a good
laboratory practice to confirm the test procedure and to verify
proper test performance.