follow up posting my Medutest result on lot C-4402, what do people make of it
#test-results 2025-08-07
Thursday47 messages9 participantstimes are UTC
Highlights from this day
- logrotate — one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally, i think 21:41
- motivation_gone — ok so a point or two between the certificate and an independent result is inside what two labs disagree by 21:53
- salt_bridge — the honest limits: hobby chain of custody is weak and any result here should be read with that in mind 22:27
- ten_of_ten — i have never regretted spending the money on a test. i have regretted not testing twice 23:22
how do you separate batch variance from supplier variance
does anyone log the negative results, the boring ones
is it worth testing if the vial has already been through a warm transit
my vial assayed under label but the purity was fine, which matters more
does a bad result on one lot condemn the whole supplier
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post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
whats the underfill rate people are actually seeing
*Janoshik not the other one
weigh it first
a single sample tells you about a single vial. that is genuinely all it tells you
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally, i think
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update from 10 months ago: retested the same supplier, result came back better, logged both
whats the lot
thats a fill problem
is anyone tracking results over time in a way they would share
thats within range
ok so a point or two between the certificate and an independent result is inside what two labs disagree by
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the results in this channel skew because people test when they are suspicious. that is selection bias and it is real
thats not great
i had a result i am fairly sure was a handling error on my side and i logged it as such
my result contradicts the supplier certificate, do i tell them
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
whats the worst result anyone has logged and what happened next
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how do you post a result so it is actually useful to somebody in a year
my sheet has 5 lots from WXT with a spread under a point, which is tight
log the lot number
what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
i test roughly every tenth vial. it is a sampling strategy, not paranoia
the honest limits: hobby chain of custody is weak and any result here should be read with that in mind
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quick one anyone had a result they think was a lab error rather than a bad vial
96.8 against a certificate of 99 is fine. the same supplier landing low four times in a row is a question
anyone tested the same lot twice at different labs
log the boring results too. a channel that only records failures produces a false picture
test it again
do the results in this channel skew because people test when suspicious
how many lots do you need before you can say anything about a supplier
which lab
i told JEEP about a result they would not have liked and they did not argue. credit where it is due
do you test every order or sample it
the widest spread in my data is about 2.6 percentage points across five lots from one supplier
one data point
underfill is more common than impurity. if you only test purity you are testing the less likely failure
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i have never regretted spending the money on a test. i have regretted not testing twice
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a supplier disputing a result is rare here and it has never gone well for the supplier
nice result
weigh the vial before you reconstitute. it costs nothing and catches the common failure
quantity testing is usually a separate line item and it is the one worth paying for