urea, C-14

Urea C-14 is a urea molecule radiolabelled with a radioactive carbon-14. Urea C-14 Breath Test is indicated for use in the detection of gastric urease as an aid in the diagnosis of H.pylori infection in the human stomach. The test utilizes a liquid scintillation counter for the measurement of CO in breath samples. To detect H.pylori, urea labeled with C is swallowed by the patient. If gastric urease from H.pylori is present, urea is split to form CO and NH at the interface between the gastric epithelium and lumen and CO is absorbed into the blood and exhaled in the breath. Antibiotics, proton pump inhibitors, sucralfate, and bismuth preparations are known to suppress H.pylori. Ingestion of antibiotics or bismuth within 4 weeks and proton pump inhibitors or sucralfate within 2 weeks prior to performing the test may give false negative results. — NCATS