Answer first: vet the documentation before you vet the supplier, because documentation is the only thing you can assess before spending anything.
Set your accept threshold before you see the result. Deciding after the number arrives is how thresholds become negotiable, and everybody does it unless they wrote it down first.
Repeat the exercise on a second lot months later. Lot-to-lot agreement is the property that actually predicts your next order, and it cannot be established from one submission.
The independent testing services this community references — Janoshik, Medutest, PeptideMeter and VendorInvestigate — publish results that can be searched by supplier, compound and date, which makes prior lots checkable.
Testing narrows uncertainty. It does not turn research-grade material into something with release testing behind it.
Two lots agreeing is worth more than one lot excelling.
5Thank you — this is the answer I was looking for. – petra_hovland 10 months ago add a comment