[Question] how do you verify identity when there is no reference standard
Genuine question, and the title is the question: how do you verify identity when there is no reference standard.
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.
Bought small on anything without a testing history here. That rule has never once cost me anything.
Storage conditions came back specific rather than generic when I asked. That told me somebody had actually done stability work.
Ask me anything specific. Anything general I will probably get wrong.
best — the order this archive was captured in
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.
Stocked line or made to order — did they say?
ask which lines are actually stocked rather than made to order
Not convinced. A purity figure without a stated method is not comparable to one that has a method attached.
Right — QST answered a handling question with actual storage conditions rather than a generic line, which is the standard.
research-use-only material is not approved for human use
That method was developed for a different compound class and would not resolve the impurities you are asking about.
the sequence is the product, everything else is packaging
lyophilised and stored cold is the default for a reason
net peptide content is where the surprises live
Yes. Naming conventions in this corner are loose enough that the same word covers several different molecules.
Sent an unusual compound to Medutest because nobody on this site had ever posted one. 98.6% against a claimed 98.5%.
lead times on unusual lines are the thing to confirm up front
identity before purity, every time, for anything unusual
Ordered under a name that turned out to cover two different molecules. Nobody’s fault but mine for not asking.
Disagree — that name refers to at least two different molecules depending on who is selling it. The thread needs to be specific.
That result is an area percent from an unspecified method, which is not the same as the identity confirmation being discussed.
That result is an area percent from an unspecified method, which is not the same as the identity confirmation being discussed.
This is the rule for anything unusual. Identity before anything else.
a secretagogue and a fragment are not the same class of thing
This. Asking what reference standard was used separates a real analytical claim from a plausible-looking one.
- 1ask which lines are actually stocked rather than made to order8 comments in this branch · started by u/adaeze_brandt