Raman is a 44 year old software engineer who has been suffering with symptoms of indigestion. He is a self employed contractor living for periods of the year in various cities across the country and admits his diet and lifestyle has been adversely affected as a result. He denies symptoms such as exertional chest pain, weight loss or dysphagia. He is a light cigarette smoker and drinks alcohol within recommended limits. Examination reveals his BMI is 28 and abdominal examination is unremarkable. It is agreed to treat his symptoms with a protein pump inhibitor and to test for Helicobacter Pylori.
Which one of the following is not used to test for Helicobacter Pylori?