Laboratory Accreditation and Quality Control

Laboratory quality is a system of controls, not a single certificate on the wall. Reliable testing requires an appropriate method, trained personnel, controlled specimens, validated instruments, acceptable quality-control results, proficiency testing, secure records, audits, and corrective action.

Certification depends on the testing program

DOT and federal workplace specimens may be tested only by laboratories certified by HHS under the National Laboratory Certification Program for the applicable specimen methodology. A laboratory’s general clinical credentials do not substitute for HHS certification when federal rules require it.

Clinical laboratories testing human specimens to diagnose, prevent, or treat disease are generally regulated under the Clinical Laboratory Improvement Amendments, administered by CMS with approved accrediting organizations and state agencies. Forensic, court, sports, and private workplace programs may require other accreditation or standards.

Scope matters

A certificate should be checked for the laboratory, location, specimen type, analyte, and method involved. A laboratory may be qualified for one service but not another. The requesting party should verify the current official directory and not rely solely on a marketing logo.

Method validation

Before routine use, the laboratory establishes that a method performs adequately for its intended purpose. Validation or verification commonly evaluates accuracy, precision, analytical sensitivity, specificity, reportable range, interference, carryover, matrix effects, stability, and measurement uncertainty where applicable.

Daily quality control

Testing batches include calibrators and controls with known expected results. Laboratories monitor trends and predefined acceptance limits. If controls fail, patient or donor results should not be released until the cause is investigated, affected testing is repeated when necessary, and corrective action is documented.

Proficiency testing and external assessment

Proficiency programs send unknown samples that the laboratory tests as routine specimens. Performance is compared with expected results or peer laboratories. Proficiency testing helps evaluate the total process, but a passing event does not replace daily controls or method-specific review.

Personnel and competency

Job qualifications, initial training, direct observation, result review, problem solving, and periodic competency assessment should match each person’s duties. High-complexity confirmation testing requires specialized technical knowledge. Access to specimens, instruments, and records should be role-based and auditable.

Inspections, audits, and corrective action

External inspectors and internal quality teams review records, facilities, security, quality controls, proficiency results, corrective actions, and compliance with procedures. A nonconformance should be assessed for root cause and impact on previously reported results. Material errors may require amended reports and notification.

Questions for a laboratory

  • Which current certification or accreditation covers this exact test?
  • Does the laboratory perform confirmation itself or refer it elsewhere?
  • What method, cutoff, and reporting limit are used?
  • How are chain of custody and specimen security controlled?
  • How are failed controls, proficiency failures, and amended results handled?
  • What records can an authorized donor or client obtain?

Quality processes support reliability, but interpretation must still match the question being asked. A technically accurate metabolite result may not establish timing or impairment.

Sources

Scientific and regulatory review: October 29, 2026.