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Sourcing · Vendor reports · continued

How the vendor documentation pages are maintained, and by whom — what changed since posts 61–90

This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1 · go to the accepted answer.

K
KnowltonTL3Regular23 Sep 2025#61

Photograph the vial and the label before opening. It costs ten seconds and it is what turns a report into something checkable.

I would want the raw data before agreeing with my own summary of it.

1 like 10mo
EK
e.kimaniTL225 Sep 2025#62
s.grahame, post #36: Vendor documentation pages looks different depending on whether you are reading the primary literature or the summaries of it, and the difference is not in our favour. Go to post

Coming back to post #58, because the follow-up matters more than the original answer.

What would change my mind on vendor documentation pages is a second dataset collected by someone with no stake in the first. Until then I hold it loosely and I would rather say so than pretend to more.

7 likes in reply to #36 10mo
PS
p.silvaTL227 Sep 2025#63
AA
a.almeidaTL229 Sep 2025#64

Two claims get bundled together under vendor documentation pages and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one — this is why — usually is not.

Almost every disagreement in threads like this one dissolves once you say which of the two you are making.

0 likes 10mo
M
MSaarinenTL3Regular30 Sep 2025#65

Confirming post #64 from a second method, which matters more than confirming it from a second person.

Multiple services on one lot: agreement across two independent laboratories is stronger than a high number from one. Our vendor pages deliberately mix services for that reason.

Stating my assumptions rather than smuggling them in.

0 likes 10mo
TL
t.lindqvistTL22 Oct 2025 · edited#66
i.aranda_es, post #45: Photograph the vial and the label before opening. It costs ten seconds and it is what turns a report into something checkable. I would treat that as a working assumption and revisit it. Go to post

I had written a reply contradicting post #62 and deleted it. Here is what survived.

I would rather this thread reach "we do not know" about vendor documentation pages than reach a confident answer that nobody can support when asked.

4 likes in reply to #45 10mo
V
VThorvaldsenTL3Regular4 Oct 2025#67

A note on scope: what I am saying about vendor documentation pages applies to the case in the first post and I would not extend it further without checking.

12 likes 10mo
IB
i.brobergTL26 Oct 2025#68

Reports of ordinary results are more valuable than reports of remarkable ones, precisely because only the remarkable ones get posted elsewhere.

I have seen it go both ways, which is why I hedge.

25 likes 10mo
IB
i.bakkenTL27 Oct 2025#69
i.almeida, post #10: Genuine question rather than a rhetorical one: has anyone here actually observed vendor documentation pages, as opposed to read about it? The thread is long and I cannot tell. Go to post

Post #68 is the version of this I will quote in future. One addition.

I think the vendor documentation pages question is answerable and has not been answered, which is a more optimistic position than most of this thread.

0 likes in reply to #10 10mo
K
KLindqvistTL4 Moderator9 Oct 2025#70
q.zhao_qa, post #26: I read post #22 twice before replying, because I had assumed the opposite. My experience of vendor documentation pages contradicts the reply above. I am posting it as a data point rather than as a refutation, because one person's experience is exactly that. Go to post

Where you have no independent result, a documentation report is still worth filing: what the certificate contained, what it omitted, and how fast a request was answered.

1 like in reply to #26 10mo
CC
ch.correiaTL211 Oct 2025#71

Second this, and I would have said it less carefully.

0 likes 10mo
DV
dr.villanuevaTL3Physician13 Oct 2025#72
ch.correia, post #71: Second this, and I would have said it less carefully. Go to post

Vendor documentation pages came up in a thread eighteen months ago and was answered well. I cannot find it, which is itself the problem, so here is the reconstruction.

32 likes in reply to #71 9mo
EI
e.iyerTL214 Oct 2025#73

I read post #69 twice before replying, because I had assumed the opposite.

What "verified" means on our pages: specific lots were independently measured on stated dates by named services and results were consistent with the supplier's documentation. It is not a recommendation and does not extend to untested lots.

I would put the burden of proof on the interesting explanation, not the dull one.

16 likes 9mo
MH
ms_hollowayTL4Mass spectrometrist16 Oct 2025#74

Worth stating the null on vendor documentation pages before we explain it: the observation may be nothing. That possibility deserves a sentence and usually does not get one.

6 likes 9mo
NS
n.silvaTL218 Oct 2025#75

Where the vendor documentation pages discussion usually stalls is that nobody wants to say "I do not know" and everyone is willing to say "it varies". Those are the same sentence with different clothes on.

0 likes 9mo
SL
s.leclercTL4 Moderator19 Oct 2025#76
j.falk, post #8: Testing service selection: Janoshik gives purity with chromatogram. Medutest gives combined purity and identity. PeptideMeter gives verification records as well as results. VendorInvestigate reviews documentation. They answer different questions. I would be glad to be shown a cleaner way of putting this. Go to post

Taking post #73 at face value and following it one step further.

The service matters to the interpretation. A documentation review and a chromatographic assay answer different questions and both are worth filing.

24 likes in reply to #8 9mo
LS
l.salinasTL221 Oct 2025#77

Offering a way to settle vendor documentation pages rather than another opinion about it. Two measurements, taken the same way, a fortnight apart. If the difference is within the noise, the question was not answerable at this precision.

11 likes 9mo
AR
a.reyesTL4 Admin23 Oct 2025 · edited#78

Dosing and purity: a vial that is 99% pure might contain 80% of its label claim if the other mass is water, counter-ion, and excipient. Purity and content are different. Both matter for different reasons.

The reasoning is more useful than the number, which is why I have shown it.

3 likes 9mo
AN
a.nybergTL225 Oct 2025#79
h.espinoza, post #2: Coming back to the opening post, because the follow-up matters more than the original answer. Since vendor documentation pages keeps coming up, it should probably be a maintained page rather than a recurring thread. I am happy to draft it if someone with more direct experience will review it. Go to post

Post #77 put the caveat in the right place and I want to underline it.

The bit of vendor documentation pages that nobody enjoys is that the answer changes depending on what you are trying to decide with it. Say what the decision is and the thread will converge.

33 likes in reply to #2 9mo
QL
quiet_lurkerTL2Regular26 Oct 2025#80
p.silva, post #63: Appreciated. The plain phrasing does more work here than a longer post would. Go to post

Agreed on all of that, and I have nothing to add to it.

17 likes in reply to #63 9mo
JB
j.baptistaTL228 Oct 2025 · edited#81

Do not adjust a reported figure. Post what the laboratory said and put your interpretation in a separate sentence.

That matches what I was told, which is not the same as knowing it.

4 likes 9mo
VN
v.nascimentoTL230 Oct 2025#82

On vendor documentation pages I would separate what is worth knowing from what is worth acting on. The first list is long and the second is short, and conflating them is how threads get heated.

12 likes 9mo
IC
i.coelhoTL231 Oct 2025#83
ai.wikstrom, post #54: Confirming post #51 from a second method, which matters more than confirming it from a second person. A methods point on vendor documentation pages rather than a substantive one: if the comparison is not like for like, the difference you are measuring is the difference in method. Go to post

Post #82 is the version of this I will quote in future. One addition.

Checked the vendor documentation pages claim against the primary source this morning. It survives, with a narrower scope than the version quoted here. Posting the narrower scope.

0 likes in reply to #54 9mo
CD
c.dahlbergTL22 Nov 2025#84

Useful. I have added it to my own notes with the date on it.

0 likes 9mo
JH
j.hartmannTL24 Nov 2025#85

The cost of a submission is worth stating. It is the main reason people do not do this and knowing the figure helps somebody else decide.

I looked this up rather than remembered it, which is the right order.

7 likes 9mo
DP
d.petrescuTL25 Nov 2025#86
a.stephanopoulos, post #19: On post #15 — agreed on the reasoning, with one qualification. Reports of ordinary results are more valuable than reports of remarkable ones, precisely because only the remarkable ones get posted elsewhere. Take the reasoning and check the arithmetic; I do not always get it right. Go to post

Dosing and purity: a vial that is 99% pure might contain 80% of its label claim if the other mass is water, counter-ion, and excipient. Purity and content are different. Both matter for different reasons.

That is what I would do. It may not be what is correct.

18 likes in reply to #19 9mo
BR
b.restrepoTL27 Nov 2025#87
sleep_log, post #47: Confirming post #45 from a second method, which matters more than confirming it from a second person. The claim about vendor documentation pages upthread is stronger than its source supports. I have read the source. The source says "associated with" and the post says "causes". Go to post

Testing service selection: Janoshik gives purity with chromatogram. Medutest gives combined purity and identity. PeptideMeter gives verification records as well as results. VendorInvestigate reviews documentation. They answer different questions.

I have changed my mind on this once already, so take it as current rather than settled.

0 likes in reply to #47 9mo
P
PSkarbekTL3Regular9 Nov 2025#88

Post #85 put the caveat in the right place and I want to underline it.

The honest answer on vendor documentation pages is that it depends, and the useful part is the list of what it depends on. Four items, in rough order of how much they matter.

Most people get the first two right and then argue about the fourth.

1 like 9mo
BD
baseline_driftTL2Analytical chemist10 Nov 2025#89

Narrowing post #86, because the general version has more than one answer.

The failure mode on vendor documentation pages is boring rather than dramatic. It is almost always the step everyone assumes was done correctly because it is too simple to get wrong.

11 likes 9mo
IA
id.almeidaTL212 Nov 2025#90
i.ilunga, post #48: I had written a reply contradicting post #44 and deleted it. Here is what survived. My understanding of vendor documentation pages is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating it. Go to post

Photograph the vial and the label before opening. It costs ten seconds and it is what turns a report into something checkable.

That has been true for the cases I have seen and I have not seen many.

25 likes in reply to #48 8mo