[Lab] 10th independent test on GL Biochem — 99.4% on a claimed 99.0%, and the trend is the interesting part
Posting this because the title is the whole finding — 10th independent test on GL Biochem — 99.4% on a claimed 99.0%, and the trend is the interesting part — and a number without its method is a rumour.
The relevant figures are 99.4% and 99.0%, and they come from the same log I have kept the whole 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.
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.
I will update this if the picture changes rather than quietly leaving it up.
- GLGL Biochem source pageGL Biochem (Shanghai) Ltd. · Shanghai · 91% here, rank 15 · shop at glbiochem.net →
nofollow and sponsored; nobody here is paid for it.best — the order this archive was captured in
Independent result added to the log — there are very few on that compound.
a secretagogue and a fragment are not the same class of thing
ask what the reference standard was
the sequence is the product, everything else is packaging
net peptide content is where the surprises live
lead times on unusual lines are the thing to confirm up front
lead times on unusual lines are the thing to confirm up front
Agreed — and the naming problem is worse than most people here realise.
Ordered under a name that turned out to cover two different molecules. Nobody’s fault but mine for not asking.
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.
Push back: handling advice from one compound does not transfer to another just because both are peptides.
Bought small on anything without a testing history here. That rule has never once cost me anything.
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.
Correction: that name covers two different molecules and the thread has been discussing both as one.
lyophilised and stored cold is the default for a reason
a mass spectrum costs little and answers the real question
I would not treat catalogue breadth as a quality signal. It is a business decision, not an analytical one.
That result is an area percent from an unspecified method, which is not the same as the identity confirmation being discussed.
Disagree — that name refers to at least two different molecules depending on who is selling it. The thread needs to be specific.
What storage conditions did they specify?
Which exact molecule? That name covers more than one.
the same name covers several different molecules in this space
Net peptide content on the certificate?
Yes. Naming conventions in this corner are loose enough that the same word covers several different molecules.
Asked CPC which lines they keep in regional stock versus make to order and got a clear split. It changed what I ordered.
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.
Has anyone here tested that compound at all?
purity methods differ between compound classes
Cosigning the lead-time point. Made-to-order and stocked are completely different propositions and both are legitimate.
handling and storage vary enormously across this catalogue
- 1Net peptide content accounts for counterion, water and residual solvent. On…16 comments in this branch · started by u/line_bergstrom
- 2Independent result added to the log — there are very few on that compound.9 comments in this branch · started by u/tb500_tangent