The CLOtest is a biopsy test used to detect Helicobacter pylori.
And is used in conjunction with an endoscope procedure whereby a biopsy from the stomach is placed in the CLOtest well.
The CLOtest rapid urease test (RUT) is a well of indicator gel sealed inside a plastic slide which sits flat and is able to be picked up with theatre gloves on. The gel contains urea, phenol red, buffers and a bacteria static agent to prevent the growth of contaminating urease-positive organisms. If the urease from Helicobacter pylori is present in the tissue sample it changes the gel from yellow to bright magenta
It has a shelf life of 18 months when stored at 2-8 degrees C. The product expires on the last day of the month indicated on the package. Do not use the product if the gel is not yellow, if the seal is damaged and the gel appears dehydrated or if the expiration date has passed.
The patient should discontinue the use of antibiotics three weeks before the biopsy. These agents may suppress but not eradicate the presence of Helicobacter pylori making the organism difficult to detect by any means. The patient should not have ingested proton pump inhibitors two weeks prior to the test as these drugs have been shown to inhibit growth of the organism in some persons.
- The recommended gastric area to biopsy is at least 2 cm away from the pylorus along the lesser or greater curve of the antrum. Excise tissue that appears normal – avoid tissue that is eroded or ulcerated as Helicobacter pylori may be present in smaller numbers around those areas. A standard biopsy forceps should render a specimen of sufficient size for the test
- If desired, an additional sample may be inserted into a single CLOtest well. Do not contaminate the second specimen with blood from the first biopsy site.
Specimen Collection and Handling
After removing the CLOtest rapid urease test slide from refrigeration, lift the label far enough to expose the yellow gel. For faster test results, allow the gel to reach room temperature before inserting the biopsy (Usually between 7 to 10 minutes).
With a clean applicator device (e.g. a toothpick etc) push the entire sample from the forceps beneath the surface of the gel to expose as much of the specimen to the gel as possible. Make sure the biopsy specimen is completely immersed in the gel.
Re-Seal the pressure sensitive label on the slide and record the patient name, date, and time the biopsy sample was inserted.
Record a positive reaction as soon as the gel changes colour. Once a positive reaction has occurred no further reading is necessary.75% of positive tests change colour with in 20 minutes. It is recommended the tests are reviewed after 24 hours as a low level positive infection may not show until then. After 24 hours the CLOtest will no longer change.