standard operating procedure (SOP)

A standard operating procedure is an authorized description of how a recurring laboratory activity is performed consistently. It defines the activity's purpose and boundaries, responsibilities, required resources, key steps, acceptance criteria, safety precautions, and records to retain. Depending on the activity, it may also address specimen requirements, quality controls, calculations, limitations, reporting, and responses to failures.

An SOP should describe the laboratory's actual approved practice in language its users understand. Copying a manufacturer insert without addressing local workflow can leave important gaps. Detail should be sufficient for the intended competent user without obscuring critical decisions. Related work instructions can carry task-specific detail, while references connect the procedure to supporting documents. Review and approval must occur before the procedure is released for routine use.

Accreditation assessment connects written procedures to observed practice and staff competence. A technically complete SOP has limited value if staff cannot find it or follow a different process. Use implementation checks, change communication, and appropriate training to confirm that revisions reach the workplace, and retain records showing which version applied when work was performed.