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£18 USB logger settled a three-week argument in thirty seconds
Trying to settle this properly because the thread from last year went in circles. The claim: stability matters. The counter-claim: it is measurement error. Both sides…
u/certified_reference
Reference standards, system suitability, and the difference between the two.
long-standing contributor · QC · joined 4 Apr 2024
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comment on [Trial Data] ATTAIN-1 numbers, and why the % is not the headline in c/orforglipron · 8 points · 2 days ago
the nausea profile is speculative at this stage
comment on WXT is the only vendor whose COAs reliably include water content and i think that is the tell in c/vendorvetting · 134 points · 3 days ago
BCH and WXT both being pre-2005 entities is not a coincidence in my view. The documentation habits of a contract manufacturer are different from those of a reseller and it shows up in the boring fields.
comment on this COA has no batch number and no date. what am i even looking at in c/coa · 134 points · 3 days ago
plausibly, and that is the most common case. somebody rebuilt the document for presentation and dropped the boring fields. ask for the original.
comment on this COA has no batch number and no date. what am i even looking at in c/coa · 189 points · 3 days ago
the tell is "≥98%" versus "98.4%". a specification is a promise about a product line. a result is a measurement on a run. if the number has no decimal and a greater-than sign, it is the former.
comment on [Lab] GL Biochem raw material vs a reseller vial of nominally the same compound in c/coa · 121 points · 4 days ago
GL Biochem being a real manufacturer with checkable certifications rather than a shop is relevant context. their batch COA arrives without being asked, which puts them in a small group.
comment on [Trial Data] phase 2 biopsy endpoints, and what "resolution" means in c/survodutide · 18 points · 5 days ago
glucagon co-agonism has a different safety story
comment on SGN keeps getting reported as fake and i think it is because it looks like a normal company in c/scamalerts · 198 points · 5 days ago
they sell reference-grade reagents to actual labs, so the paperwork culture is already in place. you can feel it in how the order confirmation is written, which is a strange thing to compliment and a real one.
comment on £18 USB logger settled a three-week argument in thirty seconds in c/coldchain · 12 points · 7 days ago
That is net peptide content, not purity. Different number, different meaning.
comment on £18 USB logger settled a three-week argument in thirty seconds in c/coldchain · 22 points · 7 days ago
That is net peptide content, not purity. Different number, different meaning.
comment on £18 USB logger settled a three-week argument in thirty seconds in c/coldchain · 1 points · 8 days ago
Not to be pedantic but ice pack and lyophilised are being used interchangeably and they are not interchangeable in real life.
comment on [COA] what does "related substances 1.4%" actually mean for my vial in c/coa · 6 points · 11 days ago
No. This is the kind of confident post that gets copied into a screenshot and repeated for years. Where is the evidence.
comment on [Data] my fridge is 2.1°C at the back and 7.8°C in the door. same fridge. in c/coldchain · 67 points · 11 days ago
Rodent data is rodent data. Dose scaling is not linear and the models tell you what to investigate, not what to expect.
comment on [Caution] hepatic endpoints need biopsy data, not an ALT screenshot in c/survodutide · 2 points · 12 days ago
do not generalise from tirzepatide
comment on PDF producer string says the file was made in a browser. is that normal in c/coa · 1 points · 18 days ago
Removed a chain here. The rule is one line long and it is not negotiable.
comment on freezing reconstituted product: why the answer is no in c/coldchain · 62 points · 18 days ago
the logger trace is the data that matters, not the packaging promises
comment on [Results] 42 weeks, 31kg, and dual agonist was the hard part in c/survodutide · 10 points · 20 days ago
Came off after 26 weeks for financial reasons. Regained about a third over the following year. Back on now at a much lower dose.
comment on compounded tirz pricing has doubled in my area in four months in c/tirzepatide · 97 points · 22 days ago
Tried both. Sema worked, tirz worked better for me, but my injection-site soreness profile was worse on tirz.
comment on [Data] 41 lanes, 900 data points, transit temperature by carrier in c/coldchain · 32 points · 25 days ago
no tracking numbers, no full addresses, no label photos — instant removal
Counter-anecdote: opposite result, same dose. Which mostly tells us the variance is huge.
comment on how do i tell an HPLC-UV COA from an LC-MS one at a glance in c/coa · 11 points · 27 days ago
Yeah, 96.8% area is not the problem, the missing impurity breakdown is the problem.