In vitro rapid diagnostic test for the detection of Clostridium
difficile antigen in human feces CE certified
The Clostridium difficile Rapid Test Cassette is a rapid chromatographic immunoassay for the
qualitative detection of Clostridium difficile GDH 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
The use of Glutamate Dehydrogenase (GDH) as an antigen marker of C.difficile proliferation has been shown to be very effective because all
strains produce high amount of this enzyme.5,6
Clostridium Cassette allows the specific detection of C. difficile's GDH in stool specimen. Samples with a positive Clostridium
Cassette result should be investigated further to test for
toxigenicity of the bacteria.
How to use?
Allow the test, specimen, stool collection buffer and/or control to equilibrate to room temperature (15-30°C) prior to testing.
- To process fecal 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 60 mg of feces (equivalent to 1/4 of a pea). Do not scoop the fecal specimen.
Hold the dropper vertically, aspirate fecal specimens, and then
transfer 2 drops of the liquid specimen (approximately 60 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.
- 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.
- Hold the specimen collection tube upright and unscrew the cap of the specimen collection tube. Invert the specimen collection
tube and transfer 3 full drops of the extracted specimen (approximately 120 mL) 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.
- Read the results at 15 minutes after dispensing the specimen. Do
not read results after 20 minutes.
- Note: If the specimen does not migrate (presence of particles),
centrifuge the diluted sample contained in the extraction buffer
vial. Collect 80 µL of supernatant, dispense into the specimen well
(S). of a new test cassette and start afresh following the
instructions mentioned above.
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 Adenovirus 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
Note: during the drying process, a very faint shadow may appear at the
Test line position. It should not be regarded as a positive result.
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.