Quality control in FISH as part of a laboratory's quality management system

Quality control in the laboratory setting requires the establishment of a quality management system (QMS) that covers training, standard operating procedures, internal quality control, validation of tests, and external quality assessment (EQA). Laboratory accreditation through inspection by an external body is also desirable as this provides an effective procedure for assuring quality and also reassures the patient that the laboratory is working to acceptable international standards. The implementation of fluorescence in situ hybridisation (FISH) in the routine diagnostic laboratory requires rigorous quality control with attention to when it is appropriate to apply the technology, a systematic approach to the validation of probes, policies and procedures documenting the analytical validity of all FISH tests performed, technical procedures involved, and a comprehensive means of reporting results. Knowledge of the limitations of any FISH test is required in relation to the probe and/or tissue being examined, since errors of analysis and interpretation can result in incorrect patient management. A structured QMS with internal quality control and regular audits will minimise the error rate.