[Quality in microbiology: contribution of the physician].

It is not always easy to choose the right microbiology test to order. Which pathogens to look for? What is the best-fitted method: microscopy, culture, tests for antigens, antibodies, genes or toxins? How to sample and transport the specimen? This article brings some answers to the questions the physician often asks when prescribing microbiology exams on stools, deep respiratory tract secretions, blood and wounds. By selecting the appropriate tests and respecting the guidelines for sampling and transporting specimens, the physician greatly contributes to the quality of results.