In the C14-urea breath test, the breath sample is read in a scintillation counter. In the C13-urea breath test the breath sample is read in a mass spectrometer (MS) rather than a liquid scintillation counter (LSC).
In the Australian TGA & US-FDA approved C14-urea breath test you fast for about 6 hours (from midnight). The test is usually performed in the morning. You swallow a capsule which contains one microCurie of C14-urea. You provide the breath sample usually by blowing up a small balloon or blowing bubbles in a small bottle of breath-collection liquid. Samples of breath are then taken 10 minutes after the capsule is swallowed. The C-14-urea contains a tiny amount of radioactive material which passes out of your body in a day or so in the urine and breath. The amount of radioactive exposure from the test is less than you will normally receive in one day from nature. (i.e. natural background radiation to which every individual on earth is exposed to everyday. The test is quick and simple to perform, and much less expensive than endoscopy. The Australian & USA version is called the"PYtest" and is described in detail at the Tri-Med breath-test internet site (http://www.trimed.com.au). In Australia the test costs $AUD80 but it is fully reimbursed by Medicare for all patients with a history of ulcer, previous H. pylori infection or for those patients unable to undergo endoscopy. However, in July 2006 the Australian Medicare Services Advisory Committee (MSAC) has recommended that public funding should be supported for the use of carbon labelled urea breath testing (both C-14 & C-13) as the first line procedure for the diagnosis of H. pylori infection. In the USA the PYtest may cost $USD50 - $USD100.
In the C13-urea breath test you fast for about 6 hours (from midnight). A baseline breath sample is collected (you blow into a bag or tube), then you eat a small, high calorie, meal ("ensure pudding" in the USA, it is somewhat like custard). Then you drink a solution of Carbon-13-urea in water. Then breath samples are taken at intervals, usually 20 40 and 60 minutes later (it varies). The samples may be mailed to a testing lab. If H. pylori present in your stomach the C13-urea will be broken down and C13 will appear in your breath. Information about the test is available at the Meretek internet site (http://www.meretek.com) and also at this health information site. The test costs about $100.