Lateral Flow Immunochromatographic Assays Clostridium difficile GDH
Rapid Test Cassette Feces
In vitro rapid diagnostic test for the detection of Clostridium
difficile GDH antigen in human feces samples For in vitro use. For
professional use only.
The Clostridium difficile GDH Rapid Test Cassette is a rapid chromatographic immunoassay for
the qualitative detection of Clostridium difficile GDH antigen in
the human feces specimen.
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 death. 4
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 difficile GDH Rapid Test Cassette allows the specific detection of C. difficile's GDH in stool specimen. Samples with a positive 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 (approximately60 µL) into
the specimen collection tube containing the extraction
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
2. 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.
3. 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 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
4. Read the results at 10 minutes after dispensing the specimen. Do
not read results after
5. 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 (T).
*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 inthe 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
Note: during the drying process, a very faint shadow may appear at
the Test lineposition. It should not be regarded as a positive
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.