[Discussion] we are measuring research peptides at the wrong time and calling it noise
we are measuring research peptides at the wrong time and calling it noise, and I am aware this is a minority view on this board. Asked WXT which lines they keep in regional stock versus make to order and got a clear split. It changed what I ordered. Sent an unusual compound to Medutest because nobody on this site had…
Why purity and net content diverge, and why that is usually honest.
Purity by area percent is a relative measure of what the detector saw. Net peptide content subtracts counterion, water and residual solvent from the powder mass. For some compounds in this catalogue the gap between the two is large.
A vial can therefore be 99% pure and contain considerably less peptide by mass than the label weight suggests, with nothing wrong anywhere. The problem is not the chemistry; it is that people compare a purity figure from one supplier with a net content figure from another and conclude something about both. Ask which number you are being shown, every time.
What lead time were you quoted for that line?
Push back: handling advice from one compound does not transfer to another just because both are peptides.
That method was developed for a different compound class and would not resolve the impurities you are asking about.
Agreed — identity first for anything off the well-travelled list. The purity number is meaningless until you know what it is pure of.
Correction: that name covers two different molecules and the thread has been discussing both as one.
Yes. Nothing in this catalogue is approved for human use and the board should keep saying so.
Yes.
ignacio_roos is right that a purity figure without a method is not comparable to one with a method.
Ordered under a name that turned out to cover two different molecules. Nobody’s fault but mine for not asking.
if nobody has tested it here, that is a fact about us, not the compound
Small fix — that is net peptide content, not purity. Both are on the certificate and they differ substantially here.