how much of what we believe about TB-500 actually comes from research peptides threads
Genuine question, and the title is the question: how much of what we believe about TB-500 actually comes from research peptides threads.
Ordered under a name that turned out to cover two different molecules. Nobody’s fault but mine for not asking.
Asked for identity confirmation on an unusual line and got a mass spectrum with the theoretical mass alongside. That is the answer I now look for everywhere.
Research-use-only material is not approved for human use. In this catalogue that covers essentially everything, which is why the board discusses material and analytics rather than outcomes.
Would rather be corrected in public than confident in private.
best — the order this archive was captured in
a mass spectrum costs little and answers the real question
Yes. Naming conventions in this corner are loose enough that the same word covers several different molecules.
Yes.
Agreed — and the naming problem is worse than most people here realise.
On the thin testing history in this board, and what to do about it.
Most of the compounds discussed here have a handful of independent results across the entire site, and several have none. That is a fact about how few members have paid for testing, not a judgement about the material.
What follows: buy small, test identity first for anything unusual, and post the result even when it is unremarkable. The vendor source pages are built from exactly these submissions, and the compounds with the thinnest coverage are the ones where one more entry changes the picture most. Research material is not approved for human use, so what this board can usefully build is an analytical record.
lead times on unusual lines are the thing to confirm up front
Yes. Nothing in this catalogue is approved for human use and the board should keep saying so.
Purity methods differ by compound class. A gradient and wavelength developed for one peptide will not necessarily resolve the relevant impurities of another.
Purity methods differ by compound class.
rekha_mbeki is right that a purity figure without a method is not comparable to one with a method.
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.
Independent result added to the log — there are very few on that compound.
Independent result added to the log — there are very few on that compound.
Adding the practical question — stocked or made to order, and what is the lead time.
Independent result added to the log — there are very few on that compound.
Disagreeing with this bit: handling for one compound does not transfer to another by default.
Net peptide content accounts for counterion, water and residual solvent. On some of these compounds the gap between purity and net content is substantial and entirely honest.
Storage conditions came back specific rather than generic when I asked. That told me somebody had actually done stability work.
Small fix — that is net peptide content, not purity. Both are on the certificate and they differ substantially here.
Correction: that name covers two different molecules and the thread has been discussing both as one.
Asked HJ which lines they keep in regional stock versus make to order and got a clear split. It changed what I ordered.
research-use-only material is not approved for human use
catalogue depth is not the same as catalogue quality
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.
Net peptide content on the certificate?
handling and storage vary enormously across this catalogue
- 1Net peptide content accounts for counterion, water and residual solvent. On…11 comments in this branch · started by u/refund_ledger
- 2lead times on unusual lines are the thing to confirm up front6 comments in this branch · started by u/sequence_checker