genuine question about tendon that I am slightly embarrassed to ask
genuine question about tendon that I am slightly embarrassed to ask. If this has been answered properly somewhere, link me and I will delete.
Assumed regulatory status was static and it was not. Checked again this year and the answer had changed where I live.
Went and read the primary rodent papers after arguing about a summary for a week. They are much narrower than the threads suggest.
Sent a vial to VendorInvestigate: 99.6% against a claimed 99.0%, with the mass confirming the sequence. Both halves mattered to me.
Would rather be corrected in public than confident in private.
best — the order this archive was captured in
The three questions, kept separate, because this board runs them together constantly.
Identity: is this the sequence I ordered? Answered by mass spectrometry against a theoretical mass. Quantity: how much peptide is in the vial? Answered by net peptide content, not by area percent. Stability: what happens to it in solution over time? Answered by a stability statement with conditions attached, and almost never asked for.
A certificate that answers one of the three is common. One that answers all three is rare and worth choosing a supplier over. Nothing here is approved for human use in any case, so all three are questions about material rather than about anything else.
Every claim I could trace in this board went back to about four papers. That was a sobering afternoon.
Every claim I could trace in this board went back to about four papers.
Disagreeing with this line: that paper is in a rodent model and it is being quoted as a human result.
Purity by area percent tells you the sample is homogeneous. Mass spectrometry tells you what the homogeneous thing is. For a short peptide, the second question is the one worth paying for.
Small fix — fifteen residues, not seventeen. The sequence is public and easy to check.
What jurisdiction are you asking about? The answer has changed in several.
Paid for identity confirmation rather than just purity for the first time here. Worth it, and it is not the default on most certificates.
Kept a reconstituted vial too long out of curiosity and learned something about solution stability I would rather have read.
That is a purity figure, not an identity confirmation. Two different tests and only one answers the question asked.
Standing reminder in every thread here: research material is not approved for human use.
Research-use-only material is not approved for human use. In this board that is not a formality — it is the reason the clinical evidence base is as thin as it is.
Asked CPC for the theoretical mass alongside the certificate and they sent it without asking why.
Bought small, tested identity first, and only then thought about anything else. That order felt right.
What method produced that purity number?
It is a fifteen-residue peptide with a published sequence, which makes synthesis straightforward and makes identity verification the meaningful test rather than an optional extra.