2.3 Good microbiological technique

Good microbiological technique refers to the basic technical methods that safeguard human errors and the misuse of equipment responsible for inaccurate results, accidents and laboratory-acquired infections (WHO, 2004). These methods ensure that specimens are transported in an appropriate container and received in a designated area, that samples are opened only by trained staff and handled appropriately when testing, and that samples are stored adequately and disposed of safely. For more about good microbiological practice see the Isolating and identifying bacteria module.

All test samples and cultures should be handled as if they are pathogenic using aseptic technique. Working aseptically creates a clean micro-environment that prevents organisms in the test samples contaminating the laboratory (a biosafety hazard), and the test samples themselves becoming contaminated with organisms from the environment. Cross-contamination is an important quality issue as it can lead to the wrong pathogen being isolated, compromising the test results. Routine checks should therefore be incorporated at various stages of the testing process to look for evidence of contamination.

Other strategies to avoid cross-contamination of samples and the workplace include careful handling of cultures and keeping the laboratory clean and tidy. Having clearly designated areas for storage of sterile, clean, used/contaminated and used/decontaminated items is recommended.