Topic summary

Revisiting: The report format the maintainers ask for, and why each field is there

Sourcing › Vendor reports batch & lot numbers Janoshik Analytical documentation quality third-party testing disputed

This is a generated summary. It shows the 9 most-liked posts from a topic of 109, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

n.kirchnerTL2 Moderator7 Jan 2026#8

BDraganov, post #5: post #4 is right about the mechanism and I think understates the practical bit. 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. Go to post

Date the report: when the analysis was done matters. Material can degrade in storage. A report from two years ago is still useful but is not evidence about the current state of the same supplier's stock.

29 likes in reply to #5 7mo

b.nwosuTL2 Moderator24 Jan 2026 · edited#14

post #13 answers the question as asked. The question underneath it is different.

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

32 likes 6mo

d.bramleyTL3Regular3 Mar 2026#30

Disputed records: when a result disagreed and was not explained, the record says disputed and stays that way. We do not remove inconvenient history; we document it.

32 likes 5mo

d.nilsenTL2 Moderator18 Mar 2026#37

h.kimani, post #6: Worth separating two things that post #2 runs together. 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. Go to post

I read post #35 twice before replying, because I had assumed the opposite.

Blind submission is worth the effort: have someone else relabel the sample so neither you nor the laboratory knows which supplier it came from until the result is back. Blind results change minds; self-selected results do not.

32 likes in reply to #6 4mo

h.vargaTL2 Moderator19 May 2026#69

ma.balogun, post #33: Date the report: when the analysis was done matters. Material can degrade in storage. A report from two years ago is still useful but is not evidence about the current state of the same supplier's stock. Go to post

33 likes in reply to #33 2mo

me.eriksenTL2 Moderator30 May 2026#75

Structured report format: compound, lot, independent testing service, method as reported, result, and the certificate figure for the same lot. One lot is one lot. It becomes a pattern at three or four, and it becomes a disputed record when asked and not explained.

31 likes 2mo

s.grigorescuTL2Member13 Jun 2026 · edited#83

m.duarte, post #11: Coming back to post #9, because the follow-up matters more than the original answer. Blind submission is worth the effort: have someone else relabel the sample so neither you nor the laboratory knows which supplier it came from until the result is back. Blind results change minds; self-selected results do not. Go to post

Lot matching: confirm the lot number on the certificate matches the lot number on the vial. A result from a different lot is not evidence about your vial.

30 likes in reply to #11 1mo

c.amankwahTL2 Moderator25 Jun 2026 · edited#90

Worth separating two things that post #86 runs together.

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.

29 likes 1mo

e.piresTL2 Moderator17 Jul 2026#103

figure_review, post #85: post #84 answers the question as asked. The question underneath it is different. 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. Go to post

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

32 likes in reply to #85 11d

Read the full topic (109 posts)

This topic was referenced in

How the vendor documentation pages are maintained, and by whom — what changed sinceSourcing › Vendor reports · 104 replies
[2026 update] Comparing documentation quality across the directory, tabulatedSourcing › Vendor reports · 3 replies

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