Quantitative Rapid Urease Test in Helicobacter Pylori Infection / 대한소화기내시경학회지

ABSTRACT

BACKGROUND/AIMS: The principle of the rapid urease test is the assessment of the color change of the pH indicator, phenol red, by ammonium and bicarbonate ions which were produced by the urease. We modified a conventional rapid urease test, and quantified H. pylori infection by measuring the change of spectrophotometric absorbance. METHODS: 202 patients with upper gastrointestinal symptoms were endoscopically examined and three biopsies were performed in each antrum and fundus. Two biopsy specimens were stained with Giemsa and scored from 0 to 4 according to the distribution of bacteria by the Wyatt method. Another specimen was used for the quantitative rapid urease test. The tissue was incubated in a cuvette containing 10% of urea solution and phenol red at 37C. We measured optical densities in 550 nm at 5 min, 10 min, 15 min, 30 min, 1 hrs, 2 hrs, 4 hrs and 24 hrs time points.