The practical answer
A chain-of-custody record shows that the material the laboratory tested is the material you took from a specific lot. It lists the sample ID, product and lot, quantity, seal number, and every handoff with date, time, name and signature. FDA's sampling manual asks that samples be sealed so they cannot be opened without evidence of tampering, and handled by as few people as possible, and notes that investigators can photograph the seal after applying it. [1]
Evidence, method & source dates ↓What chain of custody proves
An independent test result is only as useful as the link between the tested material and your lot. If a supplier disputes a result, the first question will be whether the sample really came from their lot and whether it could have been swapped or altered on the way.
FDA's 2026 Investigations Operations Manual describes a valid official sample as one that is representative of the lot and handled, identified and sealed to maintain its integrity as evidence, with a clear record of its chain of custody. It adds that as few people as possible should handle the sample, and that properly packaged samples should be opened only by the sample custodian. [1] A research lab does not need FDA's formality, but the same three habits carry over: identify, seal and record every handoff.
What the record contains
Keep the form to one page that travels with the sample, plus a copy that stays with your lot record.
| Field | Example | Why it matters |
|---|---|---|
| Sample ID | LAB-2026-041 | The identifier the laboratory reports against |
| Product, supplier, supplier lot | Product X, Supplier A, lot A1234 | Links the result to the lot and certificate |
| Container sampled | Unopened vial 3 of 5, label photographed | Shows which unit, and that it was unopened |
| Quantity sent | One sealed vial, labelled 5 mg | Lets the lab confirm what arrived |
| Seal ID | Tamper-evident label number or signed seal | Evidence the package was not opened |
| Tests requested | HPLC purity, mass spectrometry identity | Matches the lab's submission form |
| Handoffs | Released by, received by, date, time, signature | Unbroken record of who held it |
| Shipping | Carrier, tracking number, storage conditions | Covers the gap between handoffs |
| Condition on lab receipt | Seal intact, yes or no, noted by lab | Closes the chain |
Sealing and photo evidence
FDA investigators seal each sample with an official seal inscribed with the sample number, date and a single signature, apply clear tape across the seal so the package cannot be opened at any point without evidence of tampering, and may photograph the seal after applying it in case it is damaged in shipping. The manual also says never to put more than one sample in the same sealed package. [1]
A lab version: put each sample in its own bag or box, apply a numbered tamper-evident label across the opening, sign and date across it, tape over the edges without covering the writing, and photograph the sealed package with the sample ID and seal visible. Store the photos with the form. These are entries made at the time by a named person, which is what FDA's data integrity guidance means by attributable and contemporaneous records. [4]
How laboratory submission forms work
Laboratories have their own intake process, and your chain-of-custody form should feed it rather than replace it. Two examples show the range.
The Ohio State University mass spectrometry facility asks for an electronic service request through its booking system, one form for multiple samples with details attached, submitted only when samples are ready. It accepts drop-off only, at a stated room on weekdays from 9am to 4pm, does not accept radioactive or hazardous materials, delivers results electronically and discards unused sample unless pickup is requested. [2] Bio-Synthesis lists recommended sample amounts per test and asks for test-specific information: the theoretical sequence and expected composition for amino acid analysis, expected molecular weight and sequence for mass spectrometry, whether an HPLC sample is crude or purified, and the expected counterion for counterion analysis. It describes HPLC deliverables as an annotated chromatogram PDF with a purity value and method summary, with the peak table available on request. [3]
Note the last point in the Ohio State process: unused sample is discarded. If you may need a retest, keep your own sealed retain rather than relying on the laboratory to return material.
| Step | Ohio State CCIC mass spectrometry [2] | Bio-Synthesis analytical services [3] |
|---|---|---|
| Request | Electronic service request via booking system | Amounts and information listed per test on the service page |
| Information asked for | Protocol numbers where relevant, solvent, hazards | Per test: sequence, expected molecular weight, crude or purified, expected counterion |
| Delivery | Drop-off only, weekdays 9am to 4pm | Not stated on the page read |
| Results | Electronic | Chromatogram PDF, purity value, method summary; peak table on request |
| Leftover sample | Discarded unless pickup requested | Not stated on the page read |
Tying the result back to the lot
When the report arrives, check that it quotes your sample ID, that the laboratory noted the seal condition on receipt, and that the tests match what you requested. Then file the report, the form, the photos and the shipping record with the lot record, and note the result in your inventory log against the supplier lot.
If the report shows a different ID, a broken seal or tests you did not request, record the discrepancy and ask the laboratory to correct or explain it before relying on the result. ICH Q7's standard for entries is a good one to apply: made directly after the activity, identifying the person, with corrections dated, signed and leaving the original readable. [5]
Form template and pre-shipment checklist
Copy these fields into a one-page form.
- Sample ID; product; supplier; supplier lot; internal lot ID; container sampled; quantity.
- Seal ID; sealed by; date and time sealed; photo file names.
- Tests requested; laboratory; laboratory reference or quote number.
- Handoff 1: released by, received by, date, time, signatures.
- Shipping: carrier, tracking number, packed conditions.
- Laboratory receipt: received by, date, seal intact yes or no.
- Before shipping: lab submission form completed; sample ID matches form; seal photographed; retain kept; copy of this form filed with the lot record.
Questions before you decide
What is a chain-of-custody record for a lab sample?
A record that follows the sample from the lot to the laboratory: sample ID, lot, seal, and every handoff with name, date, time and signature, so the result can be tied to that lot.
Do I need a special seal?
No. A numbered tamper-evident label signed and dated across the closure, taped at the edges and photographed, follows the same logic as the seals in FDA's sampling manual.
Will the laboratory return leftover sample?
Not necessarily. Ohio State's mass spectrometry facility says unused sample is discarded unless pickup is requested, so keep your own sealed retain if you may need a retest.
What information should go to the testing lab with a peptide sample?
It depends on the test. Bio-Synthesis asks for the sequence and expected molecular weight for mass spectrometry, whether an HPLC sample is crude or purified, and the expected counterion for counterion analysis.
Check the underlying evidence
Sources & review dates
- FDA Investigations Operations Manual 2026, Chapter 4 Sampling ↗Accessed 30 Oct 2026
- Ohio State University CCIC Mass Spectrometry and Proteomics: sample submission ↗Accessed 30 Oct 2026
- Bio-Synthesis peptide analytical services: sample amounts, information required and deliverables ↗Accessed 30 Oct 2026
- FDA guidance: Data Integrity and Compliance With Drug CGMP, Questions and Answers (December 2018) ↗Accessed 30 Oct 2026
- ICH Q7 Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients ↗Accessed 30 Oct 2026
Sources are documentary evidence. They do not establish firsthand testing of a listed supplier.