What is CLO testing?
The CLO test is for Campylobacter-like organisms. At the time of endoscopy and biopsy, a pinch of tissue is removed and placed in a test solution containing urea, a pH colour reagent. The presence of H pylori results in hydrolysis of urea solution by Urease produced by H. pylori, resulting in a colour change due to pH change which occurred due to hydrolysis of neutral urea to alkaline ammonia (usually from yellow to red). In infected tissues the change in colour occurs within about one hour.
