Tool

The 12-question supplier checklist.

Twelve evidence-based markers a research-peptide supplier should be able to show. Tick what's present as you evaluate a supplier's site or COA. Higher-weighted markers carry more impact in the score.

Live score

0 / 100

Verdict

Awaiting input

identity

Mass spectrometry result on the COA (MALDI-TOF or ESI-MS), with theoretical and observed MW.

Weight · 10
Observed MW matches theoretical within ~1 Da.

Weight · 10
Peptide sequence stated explicitly on the COA.

Weight · 5

purity

HPLC purity reported as area % at a stated wavelength.

Weight · 10
HPLC chromatogram attached to the COA (not just a number).

Weight · 15
Purity above the >98% reference research threshold.

Weight · 5

content

Peptide content (%) reported alongside net peptide mass.

Weight · 10
Counter-ion identity stated (TFA, acetate, HCl).

Weight · 5

logistics

Cold-chain packaging for temperature-sensitive material.

Weight · 5
Tracked shipping with a real delivery estimate.

Weight · 5

policy

Written refund policy on the site (not negotiated case-by-case).

Weight · 10
Unique lot number on the vial label that matches the COA.

Weight · 10

How to read the score

85+ — reference-grade documentation practice. Safe to scale orders against.
70–84 — workable for chemistry-only research. Document the gaps before committing larger orders.
55–69 — borderline. Order a small reference quantity first; verify the COA against the lot.
Under 55 — walk. The cost of verifying further is higher than the cost of finding a better supplier.

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