Microbiological Data Review Checklist

In short: Use this illustrative checklist to review microbiology test records for materials, products, water and environmental samples. Analysts and reviewers should follow the applicable approved method and product requirements; this checklist does not set test conditions or acceptance limits.

Purpose and use

This checklist is a review aid for microbiology and quality-control laboratories. Adapt it to the product, sample type, applicable pharmacopoeia, approved analytical procedure and site quality system. Use the controlled method for test quantities, dilutions, incubation conditions, sample hold times, media requirements, controls, calculations and acceptance criteria. Do not infer a limit or test condition from this checklist.

For U.S. CGMP operations, 21 CFR 211.160(a) requires laboratory procedures and controls to be approved by the quality control unit and deviations to be recorded and justified. Section 211.160(b)(4) requires instrument calibration under an established written programme, with suitable intervals, limits and remedial actions. These U.S. requirements do not establish universal microbiology test conditions. 21 CFR 211.160(a), (b)(4), current eCFR.

Product, sample and method identity

Confirm that the record identifies, as applicable:

The material, product or sample, its source, batch or sample number, and sample quantity.
The manufacturer or supplier where relevant, batch size, and manufacturing and expiry dates for a product batch.
The date and location of sampling, receipt date, storage conditions and any transfer or custody information required by the method.
The analytical procedure, effective date or revision, applicable compendial reference, and any approved method modification.
The analyst, test dates and reviewer, with dates or electronic attribution recorded as required by the controlled procedure.

Check that the selected test method is suitable for the sample and that its suitability or method validation records are available where required. If the test method or a written instruction was changed, confirm that the change was approved, documented and supported by the required evidence.

General raw-data and equipment review

For each test, compare the approved method with the original worksheets, instrument files, calculations and reported result. Check that:

Raw data are complete, legible, attributable and linked to the correct sample and batch; records include relevant observations, printouts, charts, spectra or electronic data.
Sample amounts, weights or volumes, dilution factors, units, calculations and conversions are traceable and consistent with the method.
Instruments and equipment are identified, within their approved calibration or qualification status, and supported by the relevant use and calibration records.
Reagents, media, reference materials and prepared solutions are identified by lot or batch and have preparation, storage and validity details required by the method.
Controls and system suitability checks required by the method are recorded and meet its acceptance criteria.
Any deviation, atypical observation, invalidation or repeat test has an approved rationale and is linked to the investigation and final disposition.
The second-person review is documented and covers accuracy, completeness and compliance with the established method.

Example in-house criterion (not a pharmacopoeial requirement): A laboratory may use a controlled review worksheet to record which checks were completed, the reviewer’s comments and the disposition of discrepancies. Define that worksheet and escalation route in the site quality system.

For U.S. CGMP operations, 21 CFR 211.194(a) describes laboratory records, including sample identity, method, sample amount where appropriate, test data, calculations, results, performer attribution and a second-person review. Sections 211.194(b)–(d) address method changes, reference standards and reagents, and calibration records. Apply these requirements only where the U.S. regulation governs the operation. 21 CFR 211.194(a)–(d), current eCFR.

Test-specific review prompts

Use only the test-specific checks applicable to the sample and approved method. For all tests, verify that results and conclusions are calculated and reported as the method directs.

Microbial limit and enumeration tests

Confirm sample preparation, dilution series, neutralisation or filtration steps, and the plate or other enumeration method against the approved procedure.
Reconcile plate counts or other raw observations, replicate handling, calculations, units and reported results with the method’s reporting rules.
Review any identification work, investigation, repeat test or associated environmental/personnel monitoring data required by the investigation or method.

Sterility tests

Confirm sample quantity, test method, culture media, controls and incubation conditions against the applicable compendial chapter and approved procedure.
Review container or test-unit observations, growth or turbidity records, control results, preparation and media-use records, and any investigation or repeat testing.
Verify that the disposition follows the approved method and applicable quality-system procedure; this checklist supplies no sterility-test acceptance criteria.

Pharmaceutical water tests

Match the sample point, collection date and time, sampling plan and sample handling to the approved procedure.
Review microbiological and, where applicable, chemical or total organic carbon data, calculations, controls and sample hold time against the current approved method.
Check excursions, investigation records and trend conclusions against the site’s approved water system procedures and specifications.

Antimicrobial effectiveness tests

Verify the organism, culture preparation, inoculum, neutraliser or preservative inactivator, recovery checks, product quantity and test intervals against the applicable method.
Reconcile raw counts, calculations and the conclusion with the method’s acceptance criteria. Do not substitute generic limits for product-specific or compendial requirements.

Bacterial endotoxins tests

Check reagent and reference-standard identity, lot, preparation and use status; lysate sensitivity or other reagent qualification records; and sample dilution against the approved test method.
Verify that positive and negative controls, sample and reagent quantities, incubation conditions, equipment identity, calculations and result interpretation are documented as the method requires.

Media, reagents and microbiological assays

Review media identity, preparation and sterilisation records, applicable pH checks, storage and use validity, and required media quality tests against approved procedures.
For antibiotic or other microbiological assays, check sample and standard preparation, culture and media records, raw observations, calculations and conclusions against the approved assay method.
Confirm equipment IDs, calibration status and associated use records where equipment is used for a result.

Environmental, personnel and compressed-air monitoring

Compare sampling locations, sampling technique, sample volume or exposure conditions, controls, incubation and calculations with the approved monitoring plan.
Review plate or other raw counts, alert/action follow-up where defined by the site, investigations and trend conclusions.
Check that equipment and media records support the reported result and that unusual results are linked to documented assessment.

Example in-house criterion (not a pharmacopoeial requirement): Monitoring locations, frequencies, sample volumes, trend rules and escalation limits are examples of site-plan elements. Set them through the approved, risk-based monitoring programme and applicable requirements; this checklist does not prescribe values.

Particle monitoring scope

The imported checklist includes a “Particulate Matter Test” under microbiology but does not define the test. If retained, identify the method and responsible laboratory in the controlled procedure, and review sample quantity, instrument or sampling-system status, raw data, calculations and interpretation against that method.

Review outcome and retention

Record the review outcome and resolve discrepancies through the approved deviation, investigation or data-review process. Preserve the original data and the traceability between the sample, method, calculations, reviewer comments and reported result.

Retain batch-associated GMP records for at least 1 year after the expiry date of the respective product batch. Where EU GMP applies, retain batch documentation for at least 5 years after Qualified Person certification if that period is longer. Follow any longer period required by local law, the marketing authorisation or the approved site schedule. These periods are stated in 21 CFR 211.180(a) (current eCFR) and EudraLex Volume 4, Part I, Chapter 4, Revision 1 (2011), §4.11 (effective 30 June 2011). 21 CFR 211.180(a); EudraLex Volume 4, Chapter 4.

Frequently asked questions

Does this checklist replace a test method or pharmacopoeial chapter?

No. It is a record-review aid. Use the current applicable compendial text, product requirements and approved procedure for test conditions and acceptance criteria.

Which limits should the reviewer apply?

Use the limits in the approved specification and method for the sample and product. This checklist does not define microbiological limits, incubation conditions or sampling frequencies.

What should happen when data are incomplete or inconsistent?

Document the concern, preserve the original record and follow the site’s approved investigation or discrepancy process before the result is accepted or reported.

How long should batch-associated microbiology records be retained?

At least 1 year after the expiry date of the respective product batch, or longer when required by applicable law, the marketing authorisation or the approved site schedule. Under EU GMP Chapter 4, the period is at least 5 years after QP certification if longer.

References

United States, 21 CFR 211.160(a), (b)(4), “General requirements,” current eCFR version up to date as of 14 October 2026: official regulation.
United States, 21 CFR 211.194(a)–(d), “Laboratory records,” current eCFR version up to date as of 14 October 2026: official regulation.
United States, 21 CFR 211.180(a), “General requirements,” current eCFR version up to date as of 14 October 2026: official regulation.
European Commission, EudraLex Volume 4, Part I, Chapter 4, “Documentation,” Revision 1 (2011; effective 30 June 2011), §4.11: official guidance.