What laboratory quality assurance covers
Laboratory QA is the system that makes results trustworthy: not just running control samples, but controlling every step from specimen or sample receipt to the final report, and proving it with records. The rules differ by type of lab.
| Lab type | Main US framework | International standard | QA focus |
|---|---|---|---|
| Clinical (patient testing) | CLIA, 42 CFR Part 493 | ISO 15189:2022 | Pre-analytic, analytic and post-analytic quality |
| Testing and calibration | Contract or customer requirements | ISO/IEC 17025:2017 | Competence and valid results |
| Nonclinical safety studies | GLP, 21 CFR Part 58 | OECD GLP principles | Study integrity and data reliability |
| Pharmaceutical QC labs | Drug GMP, 21 CFR 211.160–211.194 | EU GMP Chapter 6 | Test methods, data integrity, OOS investigations |
Quality assurance vs quality control in the laboratory
- QC checks each run: control materials, calibration verification, acceptance of results.
- QA checks the system: procedures, competency, proficiency testing, audits, corrective action and trend review.
Under CLIA, for example, QC means running two control materials of different concentrations at least once each day patient specimens are tested for quantitative procedures, unless an approved alternative applies, with all control procedures documented. QA means the overall quality system that reviews whether those controls, and everything else, are working.
Clinical laboratories: CLIA quality systems
CLIA requires every lab doing nonwaived testing to have written policies and procedures for a quality system covering all phases of testing (pre-analytic, analytic and post-analytic) and general laboratory operations. The quality system must include a quality assessment component that continuously monitors, identifies, evaluates and resolves problems, and it must fit the lab’s specialties, tests and clients.
Record retention under CLIA
42 CFR 493.1105 sets minimum retention periods, including:
- At least 2 years for requisitions, QC and patient test records, proficiency testing records, quality system assessment records and test reports (and procedures for 2 years after discontinuation).
- 10 years for pathology test reports and histopathology slides.
- 5 years for cytology slides; 2 years for pathology blocks.
Recent CLIA changes
CMS’s updated CLIA rule went fully into effect at the end of December 2024, after delayed personnel and histocompatibility provisions took effect. Changes included revised personnel qualifications for high-complexity testing, degree equivalency requirements and fee increases. Labs should confirm personnel files reflect the new rules.
ISO 15189 and ISO/IEC 17025
ISO 15189:2022 for medical laboratories was published in December 2022 with a three-year transition ending December 2025. The new edition absorbed the point-of-care testing requirements of ISO 22870, and after the transition, accreditation to the 2012 edition is no longer recognized under the ILAC Arrangement. In 2026, accredited medical labs should be fully on the 2022 edition.
ISO/IEC 17025:2017 remains the standard for testing and calibration laboratories, including many pharmaceutical contract labs.
GLP: the quality assurance unit
For nonclinical laboratory studies, 21 CFR 58.35 requires a quality assurance unit (QAU) that is “entirely separate from and independent of” the people directing or conducting each study. The QAU must:
- Maintain a master schedule of studies and copies of protocols.
- Inspect each study often enough to protect its integrity, with signed records.
- Report problems immediately and give periodic written status reports.
- Verify that deviations from protocols and SOPs were authorized and documented.
- Review the final report against raw data and sign a QA statement listing inspection dates and findings.
Laboratory quality assurance audits
Whether internal or external, a lab QA audit usually tests:
- Document control: current, approved procedures at each bench.
- Personnel: qualifications, training and competency assessments.
- Equipment: calibration, maintenance and verification records.
- QC and proficiency testing: results, failures and corrective actions.
- Data integrity: audit trails, review of results, controlled changes.
- Specimen or sample handling: chain of custody, storage, rejection criteria.
- Reporting: report review, corrected reports and turnaround times.
- Nonconformances and CAPA: investigation quality and effectiveness checks.
Laboratory quality assurance software
Searches for lab QA software appeared in late 2025. Typical systems combine LIMS, document control, training and CAPA. Whatever the tool, labs must still validate it for intended use, control access and preserve audit trails, and be able to produce records for the retention periods above.
Common weaknesses
- QC data reviewed daily but never trended.
- Proficiency testing failures closed without root cause.
- Competency assessments overdue or undocumented.
- Procedures at the bench that differ from the controlled version.
- GLP QAU statements signed without complete inspection records.
- Records destroyed before minimum retention periods.
Checklist: laboratory QA readiness
- Written quality system covering all phases of testing
- Daily QC performed and documented per method requirements
- QC and proficiency testing trended, with documented corrective actions
- Personnel files meet current CLIA qualifications
- Accreditation transitioned to ISO 15189:2022 where applicable
- GLP QAU independent, with master schedule, inspection records and signed statements
- Records retained at least as long as regulations require
- Lab software validated, access-controlled and audit-trailed
How AskDona helps
Lab audits come down to evidence: QC logs, proficiency testing results, competency records, inspection reports and CAPA. AskDona reads that evidence against CLIA, ISO 15189, GLP or your own quality manual, shows which requirement each record supports, and flags gaps such as missing corrective actions or overdue competencies, with citations to the page. Run a sample laboratory QA audit evidence check before your next inspection or assessment. AskDona shows the evidence; your laboratory director decides.
Editor’s note: CLIA and GLP requirements are summarized from Cornell LII copies of the regulations. The CLIA rule summary comes from ASCP and contains an internal date inconsistency, so effective dates should be confirmed with CMS. ISO standards are paywalled; transition details come from ILAC. Pharmaceutical QC lab requirements are listed for context only.
FAQ
What is laboratory quality assurance? The system of procedures, controls, audits and records that ensures laboratory results are accurate and reliable across all phases of testing.
What is the difference between QA and QC in a laboratory? QC checks individual runs with control materials; QA oversees the whole system, including whether QC works.
How long must CLIA laboratory records be kept? At least two years for most records, with longer periods for pathology reports and slides.
What is a GLP quality assurance unit? An independent unit under 21 CFR 58.35 that monitors nonclinical studies, inspects them, reviews final reports against raw data and signs a QA statement.
Did ISO 15189 change recently? Yes. ISO 15189:2022 replaced the 2012 edition, with a transition that ended in December 2025.
References
All pages opened and checked by October 23, 2026.
| Source | Type | Used for |
|---|---|---|
| 42 CFR 493.1200 (LII) | Regulation | CLIA quality system |
| 42 CFR 493.1256 (LII) | Regulation | QC frequency and documentation |
| 42 CFR 493.1105 (LII) | Regulation | Record retention |
| ASCP, Jan 9, 2025 | Professional society | CLIA rule changes |
| ILAC on ISO 15189:2022 | Accreditation body cooperation | Transition and POCT |
| 21 CFR 58.35 (LII) | Regulation | GLP quality assurance unit |