Chain of Custody

A chain of custody is a documented sequence of possession. Each time a controlled item moves from one person, room, vehicle, laboratory or organisation to another, the record identifies the item, the person releasing it, the person accepting it, the date and time, and any condition information needed to judge the handover.

The item may be an incoming raw-material sample, a retained sample, a controlled substance, donor tissue, an investigation sample or a finished product. The exact fields change with the risk, but the purpose stays the same: make the history complete enough that another person can reconstruct where the item was and who was responsible for it at every stage.

Chain of custody is stronger than a movement log. A movement log can say that container A moved from room 1 to room 2. A custody record also shows the accountable people, confirms acceptance and records relevant controls such as seal condition, temperature, quantity or reason for transfer.

The three overlap but are not interchangeable. A sample can retain its identity while its custody record has a gap. A finished lot can have complete genealogy without documenting every individual who handled an investigation sample. High-risk operations often need all three records to agree.

• **Laboratory samples.** Sampling, transport, receipt, subdivision, testing, storage and final disposal may each change custody.
• **Human cells and tissues.** Donor and product identifiers must remain connected while handling and distribution records preserve the history required by the applicable framework.
• **Controlled substances.** Receipt, use, transfer and disposal need records that support accountability and reconciliation.
• **Deviation evidence.** A removed component, foreign object or failed part may need a sealed evidence history so the investigation can rely on it.
• **External testing.** Samples sent to a contract laboratory cross an organisational boundary, making dispatch, courier and receipt evidence particularly important.
• **Returned or recalled goods.** Custody and condition help determine whether returned stock can be assessed, reworked or must be destroyed under procedure.

Not every transfer needs every field. A risk assessment and procedure should define what is necessary for each item class. Collecting fields that nobody checks creates administrative weight without improving confidence.

1. **Identify the item at creation or receipt.** Assign or confirm its unique identifier before it moves.
2. **Package and label it for the next stage.** Use a container and seal appropriate to the material and journey.
3. **Record release by the current custodian.** Capture identity, quantity, condition, destination and time.
4. **Verify at the handover.** The receiver checks the identifier and condition rather than accepting an unverified package.
5. **Record acceptance or discrepancy.** Acceptance closes one custody interval; damage, a broken seal or mismatched quantity follows the defined exception route.
6. **Repeat for each controlled transfer.** Storage locations and couriers may count as custody stages when procedures make them accountable.
7. **Reconcile at disposition.** Testing, return, consumption, archive or destruction should close the record with the final quantity and decision.

• A handwritten signature that cannot be linked to a named person.
• A package left in an uncontrolled area between release and receipt.
• One identifier on the sample and a different identifier on the form.
• A courier handover with no collection or delivery time.
• A broken seal, damaged container or temperature excursion accepted without an exception record.
• Sample subdivision without recording the parent-child relationship and quantities.
• Disposal recorded without the method, witness or reconciliation required by procedure.

Paper can document custody when forms are controlled, completed at the transfer and retained securely. Its weak points are duplicate identifiers, illegible times, unsigned boxes, loose continuation sheets and delayed transcription into another system.

Electronic records can scan the item, identify the signed-in person and timestamp the event once. They can also show an incomplete expected handover for review. Those advantages depend on sound configuration, access control, reliable labels and a workable outage procedure; software does not repair a poorly defined custody process.

V5 can support the record around a custody-controlled workflow by using lot and container identities, barcode-based warehouse movements, named user records, electronic signing and audit history. The WMS module ties movements to a lot and bin, while traceability connects supplier lots, work orders, finished lots and customer shipments.

• Use a scanned container or lot identity rather than retyping it at each move.
• Keep movement and production records connected to the item they concern.
• Use signatures and audit history where your approved procedure requires accountable acceptance.
• Review exceptions and open quality records with the affected lot before a person makes a disposition decision.

1. List every material, sample and product for which possession affects identity, security or result validity.
2. Draw each normal handover from creation or receipt to final disposition.
3. Mark external boundaries such as courier collection, contract testing and customer return.
4. Define the identifier, accountable roles, condition checks and signatures for each transfer.
5. Define what happens when the receiver rejects the package or the record is incomplete.
6. Test the design by tracing a real item in both directions and timing how long reconstruction takes.

• Can one scan distinguish the item, lot, container and location without manual re-entry?
• How does the receiver record condition, quantity and a rejected handover?
• Can a sample be subdivided while preserving its parent-child history?
• What happens during an outage, and how are offline records reconciled later?
• Can we see every custody event and correction without losing the earlier value?
• Can permissions and signature requirements differ by item class and transfer type?
• Can we try our highest-risk custody path with realistic labels before committing?