Chain of Custody for Peptide Samples

Chain of custody documents who controlled a sample, where it was stored, how it was transferred, and what happened to it from receipt through disposition.

Why it matters

A highly accurate result is meaningless if sample identity is uncertain.

Core records

A chain-of-custody system may document:

• sender
• receiver
• date and time
• sample identifier
• batch number
• quantity
• condition on receipt
• seal status
• storage condition
• transfers
• testing allocation
• retained quantity
• final disposition

Tamper evidence

Tamper-evident seals, numbered containers, photographs, or documented seal checks can strengthen traceability for third-party testing.

Aliquoting

Every aliquot should retain linkage to the parent sample. New identifiers should not break traceability.

Frequently asked questions

Is courier tracking enough?

No. Courier tracking does not replace laboratory custody records.

Can a COA prove the submitted sample represented the whole batch?

Not without a justified sampling plan.

Why photograph the sample?

Photos can document label, seal, and condition on receipt.

Should discarded samples be recorded?

Yes. Final disposition should be traceable.

Key takeaways

Chain of custody connects the tested result to the physical sample. Clear identifiers, controlled transfers, and complete records are essential for defensible third-party testing.

References

1. FDA. Data Integrity and Compliance With Drug CGMP: Questions and Answers.
2. OECD Principles of Good Laboratory Practice.
3. ISO/IEC 17025 overview.

---

TSMS Labs educational disclaimer: For laboratory research and educational purposes only. Not for human consumption. This content is not medical, clinical, or regulatory advice.