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Lot traceability

Every number we publish was measured for that lot

Enter a lot number and you get that lot's release panel — the measured result, not a representative example. Where a panel was run by the manufacturer who released the batch rather than by us, the page says so and names them.

Certificate of analysis

TB-500

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Purity by HPLC

99.80%

Lot
AB110125S1
Reported
2025-12-03
Tested by
Chromate
Label claim
10 mg
Measured
11.89 mg
  • AppearanceVisualLyophilized peptide vialReported
  • IdentityRP-HPLC-UVTB-500 (TB4 fragment 17-23)Pass
  • PurityRP-HPLC-UV99.796%Pass
  • QuantityRP-HPLC-UV11.89 mgReported

Manufacturer’s certificate. This panel was run by Chromate and issued to Step One Ventures, who released the batch this material came from — it is their testing, not ours, and the lot number above is theirs. We publish it as the incoming-goods record for the material we bought.

The results above are transcribed from the signed certificate. Ask us for a copy and we will send it.

Ask us for the signed certificate

AFA Biosciences · Verified

Certificate of analysis library

Every released lot, with the panel its laboratory actually ran. Search a lot number, a compound or a laboratory. The results shown here are transcribed from each signed certificate; ask us and we will send the original.

29 released lots · 14 awaiting

Awaiting a certificate · 14

These products have no released lot on file yet. The certificate is published here, against its lot number, as soon as it arrives.

The release panel

What is measured, and what is not

Eight assays matter for a peptide reference material. 2 are on every certificate we hold — purity and content or quantity; the rest are run on some lots or not yet at all. Each one below says which, counted from the certificates on this page rather than asserted. A lot that fails an assay it was given is withdrawn rather than downgraded and sold on as a lower grade.

  1. 01

    Appearance

    Visual

    On 19 of 29 lots

    Color, cake integrity and absence of visible particulates, checked against the specification for the sequence.

  2. 02

    Purity

    Analytical HPLC · 214 nm

    On all 29 lots

    Reverse-phase C18, gradient elution. Purity is area percent of the main peak against the total integrated area — not against a hand-picked subset of peaks.

  3. 03

    Identity

    ESI mass spectrometry

    On 21 of 29 lots

    Electrospray ionization confirms the molecular ion against the theoretical mass. Both numbers go on the certificate so you can check the arithmetic yourself.

  4. 04

    Net peptide content

    HPLC vs. reference standard

    On all 29 lots

    How much peptide is actually in the vial, as distinct from fill weight. We publish both, because the gap between them is real and most sellers quietly leave it out.

  5. 05

    Water content

    Karl Fischer titration

    Available on request

    Residual water in the lyophilized cake. It matters because water is mass you paid for and did not want, and because it drives long-term stability.

  6. 06

    Heavy metals

    ICP-MS

    On 1 of 29 lots

    Screened for the elemental impurities that carry through from reagents and hardware.

  7. 07

    Bioburden

    Plate count

    On 4 of 29 lots

    Microbial growth on the released material. A lyophilized cake is not sterile by default and should not be assumed to be.

  8. 08

    Endotoxin

    USP <85>

    On 11 of 29 lots

    Bacterial endotoxin load, reported as a figure rather than a pass mark, so you can judge it against whatever your own work requires.

Whose testing this is

Every certificate published here was issued to the manufacturer who released the batch, not to us, and each one names that laboratory and that client on its face. It is their release testing on the material we bought, which is what our incoming-goods check rests on — not testing we commissioned, and we do not present it as such. The lot number on a certificate is theirs.

If your own assay ever disagrees with one of these certificates, send it to us. We will have the material re-tested independently, and if it is genuinely off specification we will refund the affected order in full, withdraw the remainder and reimburse your testing cost.