LabKate said:The useful checklist is about verifiability rather than presentation.
I disagree that testing history is decisive. It tells you what a supplier did when they were being watched. Continuity of behaviour under stress — a late shipment, a failed test, a complaint — is more predictive than any run of good results.
Dr.PainCLE said:Eight months with one supplier, then a change in how they communicate that I noticed before I noticed anything about the product.
Vendor reputation tracking for vendor vetting: I maintain a personal spreadsheet with every order I've placed — date, vendor, batch number, Janoshik result, personal efficacy assessment (1-5 scale), and any issues.
After 14 orders across 5 vendors: average purity 97.6%, zero sterility concerns, 0 shipping issues (all resolved). This data gives me confidence in my current source and documentation if issues arise.
I encourage everyone to track their orders systematically. Community data aggregation makes us all safer.
BethLabQueen said:I disagree that testing history is decisive.
Adding the part of the answer the thread has not reached. Take it one variable at a time. Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent argument can untangle them after the fact.
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Shop Reference StandardsA narrower follow-up, since the general answer is now clear:
How people are distinguishing a supplier having a bad batch from a supplier on the way out?
Reporting back.
Went back through my own correspondence with an earlier supplier and the warning signs were all there in the replies, weeks before the quality changed. I was reading the product and not the behaviour.