Sample lifecycle in LIMS: identification and chain of custody

Two aliquots come from the same sample, but one loses its readable label. Creating a new record may appear to solve the problem while breaking its relationship with tests and results. The sample lifecycle in LIMS must make identity, location, status and responsibility reconstructable, including exceptions.

1. Identify and accept the sample

Define an identifier that is unique across the actual scope, including sites, systems and imports. Preserve the links to material, batch, request, origin, sampling and container; do not rely solely on free-text names. Distinguish sampling, receipt and registration dates: they may coincide but represent different events.

On receipt, record relevant quantity and conditions, container integrity, required information and the acceptance decision under the applicable procedure. Uncertain identity or an unacceptable condition requires authorised handling before use. LIMS can document the assessment; it cannot infer material suitability because a code scans successfully.

Representativeness depends on the sampling plan and its execution. A correct code does not demonstrate it. QC LIMS requirements should reflect these distinctions without silently transferring scientific responsibilities to software.

2. Connect the sample, aliquots and preparations

Model the original material, aliquots and preparations requiring their own identity separately. Each derivative retains its relationship with its parent and the operation that created it, including operator, date, quantity or other relevant information. An explicit relationship is more dependable than similar names.

Subdivision does not automatically mean new sampling; a preparation is not necessarily a new aliquot. Define these entities in the process and verify that tests and results point to the right object. Where an operation involves several materials, record all necessary relationships rather than forcing a single parent that conceals the activity.

Each container needs distinguishable identity, position and status. Moving the original sample in the system must not automatically move aliquots located elsewhere. Physical preparation instructions belong in PL-03; storage instructions belong in the relevant PL-04 topics.

3. Control states and custody transfers

Define which roles may receive, assign, start tests, hold, review and close the lifecycle. The following matrix is a design example: state names, controls and role separation must be adapted to the approved process.

A scan shows that an event was recorded; it does not alone prove physical arrival or preservation of required conditions. For critical transfers, provide receiver confirmation and discrepancy handling. If entry is late, retain the stated actual event time and entry time with a verifiable explanation rather than silently backdating.

4. Handle labels, cancellations and exceptions

An authorised reprint retains the identity of the container concerned and records the reason, operator and event. Check agreement among record, container and replacement label; control the previous label under the procedure to reduce mix-ups. Do not assign identity solely from a rack position where evidence is insufficient.

If identification remains uncertain, suspend use and initiate the prescribed assessment. A damaged container also requires an assessment of material integrity: fixing the label does not resolve loss, contamination or exposure. Decisions to transfer, reject or resample must be authorised and linked to the history.

Reconcile requested, completed, cancelled and open activities against results and derivatives. Cancellation retains its reason and attribution; it does not erase existing data. For instrument results, interface reconciliation must cover sample and test identity as well as numerical values.

5. Simulated case: reprinting an aliquot label

Fictitious sample C-240 produces C-240-A and C-240-B. A is assigned to a test; B remains in storage. Before use, A’s label becomes difficult to read. The operator pauses the step and uses evidence allowed by the procedure to verify identity, without inferring it solely from proximity to B.

If verification is sufficient, the authorised reprint retains C-240-A and its link to C-240. The record retains the reason, responsible person and reprint time; the test continues to reference the same aliquot. If identity cannot be demonstrated, the pathway remains on hold for the prescribed decision: C-240-C is not created to evade the uncertainty.

At closure, reconcile A’s test and B’s destination. Retention, return or disposal depends on applicable obligations, stability and procedures; there is no universal duration. Record authorisation and the completed material disposition while retaining records for the required period. Closing the digital record does not physically dispose of the container.

6. Sources and applicability

Sources checked: 2 October 2026. GMP context for human medicinal products. Matrix and case are original illustrations; no real samples are handled.

• European Commission — GMP Chapter 6, March 2014 revision, effective 1 October 2014, §§6.7–6.17: documentation, sampling, identification and test records.
• European Commission — GMP Chapter 4, January 2011, effective 30 June 2011, §§4.1, 4.8–4.12: record relationships, recording, corrections and retention.
• European Commission — Annex 11, January 2011 revision, effective 30 June 2011, §§6, 9 and 12: accuracy, history and attribution in computerised systems. The 2025 proposals are not treated as adopted texts.