98.6 against a certificate of 96.8 is fine. the same supplier landing low four times in a row is a question
#test-results 2026-02-21
Saturday33 messages6 participantstimes are UTC
Highlights from this day
- underfill_uma — how do you post a result so it is actually useful to somebody in a year a result without a lot number and a purchase date is an anecdote with a pdf attached 13:01
- VialBot — Reminder set. I will post here in 9 days. 14:56
- assay_not_purity — if the vial has been through a bad transit you are testing the transit as much as the supplier, someone check my working 16:27
- endotoxin_ed — quick one a single sample tells you about a single vial. that is genuinely all it tells you 16:29
- endotoxin_ed — does anyone log the negative results, the boring ones 16:58
how many lots do you need before you can say anything about a supplier
do the results in this channel skew because people test when suspicious
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem
thats a fill problem
weigh the vial before you reconstitute. it costs nothing and catches the common failure
i test roughly every tenth vial. it is a sampling strategy, not paranoia, i could be wrong
[edited]log the lot number
quick one a supplier disputing a result is rare here and it has never gone well for the supplier, your mileage will differ
the honest limits: hobby chain of custody is weak and any result here should be read with that in mind
is quantity testing available as a separate thing or bundled
is it worth testing if the vial has already been through a warm transit
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
unrelated but my vial assayed under label but the purity was fine, which matters more
i have never regretted spending the money on a test. i have regretted not testing twice
*Janoshik not the other one
posting my Medutest result on lot B-0329, what do people make of it
when did you buy it
how do you post a result so it is actually useful to somebody in a year
a result without a lot number and a purchase date is an anecdote with a pdf attached
| Evidence | Counts? |
|---|---|
| Independent report, lot you bought, lot number legible | yes |
| Independent report, no lot number | no |
| Supplier certificate only | no |
| Screenshot of a report | no |
| Blinded pooled submission | yes, for the pool |
| A friend who said it was fine | no |
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally, ill dig out the number
one data point
the widest spread in my data is about 2.6 percentage points across five lots from one supplier
do you test every order or sample it
update from 26 months ago: retested the same supplier, result came back better, logged both, we shall see
Reminder set. I will post here in 9 days.
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log the boring results too. a channel that only records failures produces a false picture
selection bias
underfill is more common than impurity. if you only test purity you are testing the less likely failure
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sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
thats within range
if the vial has been through a bad transit you are testing the transit as much as the supplier, someone check my working
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quick one a single sample tells you about a single vial. that is genuinely all it tells you
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ok so i told QYB about a result they would not have liked and they did not argue. credit where it is due
does anyone log the negative results, the boring ones
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