[Lab] split one vial across VendorInvestigate and PeptideMeter — 94.2% and 96.8%
Short version of the title, which is already short: split one vial across VendorInvestigate and PeptideMeter — 94.2% and 96.8%. Longer version underneath. Figures up front so nobody has to dig: 94.2% and 96.8%. On the thin testing history in this board, and what to do about it. Most of the compounds discussed here…
The three questions to ask before ordering anything from the long tail of a catalogue.
What exactly is it — catalogue number or sequence, not a common name, because several common names map to more than one molecule. How was identity established — mass against theoretical, ideally, rather than a bare purity figure. What are the storage conditions, stated specifically, with a state and a duration attached.
Then two commercial questions that save time: is this a stocked line or made to order, and what is the lead time in writing. All five are one email, and the shape of the reply tells you a great deal before any material moves.
Confirmed the lead time in writing before ordering a made-to-order line. It was longer than the site suggested and entirely reasonable once explained.
Correction: that name covers two different molecules and the thread has been discussing both as one.
lyophilised and stored cold is the default for a reason
That method was developed for a different compound class and would not resolve the impurities you are asking about.
research-use-only material is not approved for human use
Storage conditions came back specific rather than generic when I asked. That told me somebody had actually done stability work.
catalogue depth is not the same as catalogue quality
Identity confirmed, or purity only?
Small fix — that is net peptide content, not purity. Both are on the certificate and they differ substantially here.