One of the main tasks of the laboratory incharge of a clinical microbiology laboratory is to provide detailed guidelines for the collection and transportation of the specimens obtained from the patient. Improper collection and delay in transportation may result in overgrowth of normal microbiota prevailing at the site of collection, outgrowing of opportunistic flora and death of labile, fastidious but more virulent organisms which are in fact might be the cause of the infection. Paradoxically medical students become acquainted with the molecular biology and genetics of microbiota but are less likely to even suspect the role of microorganisms in the pathogenesis. The optimal time for collecting the specimen depends to certain extent the type of infectious disease process and the ability of the laboratory staff to process the sample.