The PCR (Polymeric Chain Reaction) is a type of diagnostic test that has been used for years in different public health crises, related to infectious diseases. When performing a diagnostic test by PCR, what it allows to detect is a fragment of the genetic material of a pathogen or microorganism. The PCR, whose use is common and routine in the microbiology laboratories of hospitals, research centers and universities, is based on the heat stability characteristics of a polymerase enzyme. After analysis in a Microbiology laboratory of a respiratory sample from a person suspected of being infected, if the test detects RNA of the virus, the result is positive. Thus, it would be known that this patient has Covid-19. On the other hand, if the PCR technique does not detect the genetic material of the virus, the person would not be infected. At Doctor Mallorca® we take the nasopharyngeal sample from our patients and send it to the central laboratory, the result is delivered via e-mail within 18-24 hours (under normal conditions, although on rare occasions it may take up to 28 hours), our patients receive an e-mail with the result that is totally valid certificate required for all countries. Please Note: we always recommend that our patients carefully review the pages of the health ministries and institutions of their own governments to assess what type of test is valid and what the requirements are. Many of the countries of the European community consider the antigen test sufficient, which unlike PCR, has a much lower cost and takes only minutes to provide a result.