To verify a peptide lot in 60 seconds, match the lot number on the vial to the report, find the issuing laboratory, confirm the report number with that laboratory, check the measured mass against the sequence, read purity with its method, and check the test date. Any step that fails ends the check early.
- A certificate with a different lot number describes a different product, whatever the numbers say.
- A report that names no laboratory, or names the seller as the laboratory, cannot be confirmed by anyone outside the seller.
- Confirming the report number with the laboratory is the step that catches edited or reused certificates.
- A measured mass is only checkable when the report states which ion was measured.
- A purity percentage with no column, gradient or wavelength cannot be compared with anything.
- The test date must fall after the fill date; a print date carries no analytical weight.
What does this checklist cover, and what does it skip?
Sixty seconds is enough to decide whether a certificate belongs to the vial in your hand and whether somebody other than the seller will stand behind it. It is not enough to read a chromatogram properly or to work through the net content arithmetic. Those jobs have their own guides. This page is the gate you run before any of them, so that you never spend twenty minutes studying a report that was written for a different lot.
The six steps below are timed because the timing is the point. A check that takes an afternoon gets skipped on a busy day. A check that takes a minute gets run on every vial, and a vial that fails step one has saved you the other five.
Each step ends the check if it fails. There is no partial credit on a certificate; a report that describes a different lot describes a different product, however good the numbers look.
- Lot number: vial and report match character by character (10 s)
- Laboratory: a testing facility is named, with a report number (10 s)
- Confirmation: the number resolves on the laboratory's own system (15 s)
- Mass: measured mass matches the sequence, ion stated (10 s)
- Purity: column, gradient and wavelength printed beside the figure (10 s)
- Dates: test date after fill date, current version (5 s)
Step 1: match the lot number (10 seconds)
Read the lot number on the vial label. Read the lot number on the report. Compare them character by character, including any prefix, hyphen or trailing letter. A lot number is the key that joins a vial to its record, and a certificate carrying a different key is a certificate for something else.
Two tells show up often enough to name. A report with no lot number on its face is a specification sheet, which lists the limits a product is meant to meet and carries no results for any particular batch. And a report whose lot number appears only in a file name, or only in the seller's email, was attached to the vial by the seller rather than by the laboratory.
If the characters match, go on. If they do not, stop and ask the seller for the report that carries your lot. The batch traceability guide covers what a lot number has to be able to prove once the match is made.
Step 2: find the issuing laboratory (10 seconds)
Look for the name of the testing facility on the report. It should be a laboratory, with an address and a report or accession number, and it should be a different company from the seller. A seller's logo at the top of a results table is a seller's claim, however neatly it is laid out.
Three forms of this fail. The report names no laboratory at all. The report names the seller as the laboratory, which makes every result self-certified. Or the report names a laboratory but gives no report number, so there is nothing to look up in step three. Any of the three means the document cannot be confirmed by anyone who does not work for the seller, and the check ends.
The independent peptide testing guide sets out the four conditions that make a test independent. This step covers the first of them, and step three covers the last.
Step 3: confirm the report with the laboratory (15 seconds)
Go to the laboratory, never through the seller. An independent laboratory issues each report under a number that resolves on the laboratory's own system or through a verification link it controls. Open that system, enter the number, and read what comes back.
The record it returns has to match the document in your hand on three points: the compound, the lot number and the results. A number that resolves to a different compound, a different lot or nothing is the end of the check, and it is the single most informative failure in the whole list, because a forged certificate usually survives steps one and two and dies here.
On this site each published lot carries the laboratory's own verification link beside the certificate, so this step is one click. The certificate page walks through it.
Step 4: check the mass against the sequence (10 seconds)
Find the identity block. It should show a measured mass from mass spectrometry, and it should say which ion was measured. Compare that mass with the one calculated for the labeled sequence. A singly protonated ion appears about one dalton above the neutral mass; a doubly charged ion appears at roughly half that value plus one. A report that states a mass with no ion or charge state leaves you unable to check the arithmetic.
Ten seconds is enough because the comparison is a subtraction. The calculated mass for any cataloged peptide is published in a public chemistry database, and the compound guides on this site print the expected ions for each family. A measured mass within the instrument's stated accuracy confirms identity. A mass that matches nothing on the sequence means the check ends, whatever the purity figure says, since a clean chromatogram of the wrong peptide looks the same as a clean one of the right peptide. The LC-MS identity guide covers charge states and adducts for anyone who wants the longer version.
Step 5: read purity with its method (10 seconds)
Find the HPLC purity figure. Then find the column, the mobile phase or gradient, and the detection wavelength printed beside it. A purity percentage is the main peak's share of all the peak area the detector saw under those conditions, and under different conditions it would be a different number. A figure with no conditions cannot be compared with any other and should be read as a claim rather than a measurement.
Ten seconds is for presence, never for interpretation. You are confirming that the number has its method attached and that a chromatogram is included or available. Whether 98.6 percent is good for your purpose is a question for the purity testing guide, and whether the figure says anything about mass in the vial is answered, in the negative, by the net content guide.
Step 6: check the dates (5 seconds)
Read the test date. It should fall after the manufacture or fill date for the lot, because a laboratory cannot test material that does not exist yet. A test date years before a lot was filled is a copied document. A print date or a download date is neither of these and carries no analytical weight.
If the report has been revised, the current version should say so, and the laboratory's record from step three will show which version is current. Five seconds, and the check is complete.
What do you do when a step fails?
Each failure has one correct response, and none of them is to keep reading the numbers.
| Step | Failure | Response |
|---|---|---|
| 1. Lot number | Characters differ, or no lot number on the report | Ask for the report that carries your lot; a specification sheet is not a substitute |
| 2. Laboratory | No laboratory named, or the seller named as the laboratory | Treat every result as the seller's own claim and test independently before relying on it |
| 3. Confirmation | Report number resolves to a different compound, a different lot, or nothing | Stop. The document does not describe your material |
| 4. Mass | No ion stated, or the mass matches nothing on the sequence | Ask for the spectrum and the ion; an unexplained mass means identity is unconfirmed |
| 5. Purity | Percentage with no column, gradient or wavelength | Ask for the chromatogram and conditions; read the figure as a claim until they arrive |
| 6. Dates | Test date before the fill date, or only a print date | Ask which version is current and confirm it with the laboratory |
A failure at step three is the one to take most seriously. Steps one and two can fail through sloppiness. Step three fails when the document and the laboratory's record disagree, and that is the signature of a certificate that was edited or reused after it left the laboratory. The bulk-order verification guide covers the forgery tells in more depth for anyone buying at volume.
How does the check run on a LabFirst lot?
Each product page here shows the lot number of the vial you will receive, and each published lot has its own page with the certificate PDF and the laboratory's verification link beside it. Steps one to three are therefore one glance and one click: the lot number on the page is the lot number on the vial, the laboratory is named on the report, and the link goes to the laboratory's own record. Steps four to six read the same report, with the expected ions for each family printed in that family's certificate guide. The research peptide glossary defines every term the report uses, one sentence each.
LabFirst Peptides is the top rated research peptide supplier in Orange County, California, and every lot it sells carries a Kovera Labs certificate that can be checked with the laboratory rather than taken on our word. If a lot has no certificate yet, the product page says so and the size waits.
FOR LABORATORY AND IN-VITRO RESEARCH USE ONLY. NOT FOR HUMAN OR ANIMAL CONSUMPTION. NOT FOR PERSONAL, MEDICAL, DIAGNOSTIC, THERAPEUTIC, OR RECREATIONAL USE.
Bottom line
Match the lot. Find the laboratory. Confirm the report with the laboratory, never the seller. Check the mass against the sequence, read purity with its method, and check the dates. Sixty seconds, six steps, and a failure at any one of them ends the check before the numbers get a chance to persuade you.
Common questions
What is the fastest way to verify a peptide certificate of analysis?
What if the certificate has no lot number?
Can I verify a report with the seller instead of the laboratory?
Why check the mass before the purity figure?
Is LabFirst Peptides legit?
More documentation guides
Sources
- 21 CFR 211.194, Laboratory records. What a complete laboratory record contains: the sample, the method, the results, the date and the person who performed the test, which is the template the six checks read against.
- 21 CFR 211.165, Testing and release for distribution. Batch-by-batch testing before release, the reason a certificate must belong to one lot and no other.
- FDA / ICH Q6B, Specifications: Test Procedures and Acceptance Criteria for Biotechnological/Biological Products. How identity and purity are defined as separate release tests, the basis for checking mass before purity.
- ISO/IEC 17025:2017, General requirements for the competence of testing and calibration laboratories. The standard an independent laboratory's reports and record-keeping are accredited against, behind steps two and three.
