[Lab] sequence check before price check. every time.
Filing this under things worth writing down: sequence check before price check. every time.
Purity methods differ by compound class. A gradient and wavelength developed for one peptide will not necessarily resolve the relevant impurities of another.
Storage guidance that names a temperature, a state and a duration reflects actual stability work. Generic guidance usually reflects a template.
Stocked lines and made-to-order lines have different lead times and different storage histories. Both are ordinary; the difference is worth confirming before you commit.
Screenshot none of this. Read the whole thread, including the parts where I am told I am wrong.
best — the order this archive was captured in
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.
Naming in this space is inconsistent. Several widely used names map to more than one molecule, so a catalogue number and a sequence beat a common name every time.
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.
handling and storage vary enormously across this catalogue
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.
ask which lines are actually stocked rather than made to order
if nobody has tested it here, that is a fact about us, not the compound
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.
the sequence is the product, everything else is packaging
lead times on unusual lines are the thing to confirm up front