Book excerpt: This handbook was designed to be used by laboratory and other medical personnel responsible for collecting and transporting specimens to the bacteriology laboratory. The handbook should also be of value to personnel responsible for hospital epidemiology and nosocomial infection control. The microbiology laboratory plays a critical role in successful patient care, but the value of its reports is dependent upon the first step in specimen handling-that is, selecting, collecting, and transporting the specimen to the bacteriology laboratory. In the final analysis, the clinical bacteriology laboratory can be of little value to the physician and thus offer only minimal service to patient care if specimens are improperly collected and submitted for the isolation and identification of microorganisms. Microbiologists must be aware also that misleading or insignificant information reported to a physician can be as harmful as incorrect results.