Abstract: The present invention relates to a new solution for the preparation of stool samples for diagnostic tests. The solution allows samples to be prepared simply before use in an immunological detection process and also provides a high level of sensitivity, specificity and reproducibility of the tests. The solution must contain at least one buffer substance, one detergent and one blocking reagent. The Invention also relates to a process for the analysis of a stool sample for diagnostic purposes using the solution according to the invention.

Abstract: The invention relates to a method for detecting an infection of a mammal with an acid-resistant microorganism, wherein (a) a stool sample of a mammal is incubated with at least two different monoclonal antibodies, fragments or derivatives thereof or aptamers under conditions allowing a complex formation of antigens of the acid-resistant microorganism with antibodies, fragments or derivatives thereof or the aptamers, and wherein (aa) the first monoclonal antibody or the fragment or the derivative thereof or the first aptamer specifically binds an epitope of the first antigen, which shows at least with some mammals a structure after the intestinal passage that corresponds to the native structure or the structure which a mammal produces antibodies against after being infected or immunised with the acid-resistant microorganism or an extract or lysate thereof or a protein therefrom or a fragment thereof or a synthetic peptide; (ab) the second monoclonal antibody or the fragment or the derivative thereof or the sec