Detection of Helicobacter pylori antigen in stool

Detection of Helicobacter pylori antigen in faeces is an alternative to the breath test. It is the basic method for detecting Helicobacter pylori infection. The method was developed as a classical ELISA and is performed on standard microtiter plates for 96 samples. The stool sample is prepared at a concentration of 200 mg / ml and centrifuged at 7000 × g for 5 minutes. Then ELISA with tetramethylbenzidine as substrate and photometric evaluation at 450 nm is performed. There are several modifications of the ELISA method that achieve a specificity and sensitivity of 98%. The original method (HpSAg) used polyclonal antibodies, newer methods with monoclonal antibodies show higher diagnostic parameters. With regard to the sampling, the method is not demanding for the patient, the laboratories have sampling containers with a plastic core in the form of a spoon, by which the stool sample is taken and closed. Stool samples can be stored at -20 ° C for several months.

Recently, quick so caller rapid tests on the immunochromatographic detection principle, designed for individual examinations, have also appeared. However, the reliability of these rapid tests is lower compared to the ELISA method, the results of rapid tests may be affected by stool collection.