[Discussion] the TB-500 advice in here is 2 years out of date
the TB-500 advice in here is 2 years out of date, which sounds obvious until you try to state the evidence for it. To save the first four comments: 2 years. 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…
For any compound with a thin testing history, identity is the first question. Mass spectrometry against a theoretical mass answers it; an area-percent purity figure does not.
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.
the same name covers several different molecules in this space
Push back: handling advice from one compound does not transfer to another just because both are peptides.
Ordered under a name that turned out to cover two different molecules. Nobody’s fault but mine for not asking.
Ordered under a name that turned out to cover two different molecules.
This is the rule for anything unusual. Identity before anything else.
This is the rule for anything unusual.
Adding the practical question — stocked or made to order, and what is the lead time.
purity methods differ between compound classes