For your Information... How does CLO test work?

The CLO test is a rapid test for the diagnosis of Helicobacter Pylori, which secretes the enzyme "Urease".

The CLO test takes advantage of this chemical reaction to test for the presence of Helicobacter Pylori. The biopsy specimen from an OGD is placed into medium containing urea and indicator phenol red. When the Urea is hydrolysed by the H. Pylori in the specimen into NH₃, the pH is raised and the indicator changes from yellow to RED.

The CLO test works by detecting when the medium becomes ALKALINE due to the ammonia.

This is in stark contrast to the Urease Breath Test, which detects the CO₂ (via C¹³ labelled urea) produced from the reaction.