a single sample tells you about a single vial. that is genuinely all it tells you
#test-results 2026-01-19
Monday46 messages11 participantstimes are UTC
Highlights from this day
- one_data_point — if the vial has been through a bad transit you are testing the transit as much as the supplier, thats one data point 17:53
- one_data_point — how do you post a result so it is actually useful to somebody in a year 18:02
- chaser_chris — my sheet has 9 lots from MKM with a spread under a point, which is tight 19:08
- ring_size_down — i had a result i am fairly sure was a handling error on my side and i logged it as such, anyway 19:47
- ring_size_down — i told CPC about a result they would not have liked and they did not argue. credit where it is due 20:14
has a supplier ever disputed a result posted here
nice result
selection bias
a supplier disputing a result is rare here and it has never gone well for the supplier, ymmv
genuine question update from 26 months ago: retested the same supplier, result came back better, logged both
if the vial has been through a bad transit you are testing the transit as much as the supplier, thats one data point
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how do you post a result so it is actually useful to somebody in a year
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thats not great
posting my Janoshik result on lot C-4402, what do people make of it
i have never regretted spending the money on a test. i have regretted not testing twice
which lab
the results in this channel skew because people test when they are suspicious. that is selection bias and it is real
log the boring results too. a channel that only records failures produces a false picture, ymmv
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
my sheet has 9 lots from MKM with a spread under a point, which is tight
one data point
a point or two between the certificate and an independent result is inside what two labs disagree by
underfill is more common than impurity. if you only test purity you are testing the less likely failure, thats just me
when did you buy it
coming back after 15 months with a follow up result, where do i put it
weigh it first
certificate said 99.4 and the independent came back 97.4, is that a problem
is it worth testing if the vial has already been through a warm transit
i had a result i am fairly sure was a handling error on my side and i logged it as such, anyway
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weigh the vial before you reconstitute. it costs nothing and catches the common failure
is anyone tracking results over time in a way they would share
the widest spread in my data is about 2.6 percentage points across five lots from one supplier
quick one the honest limits: hobby chain of custody is weak and any result here should be read with that in mind
i told CPC about a result they would not have liked and they did not argue. credit where it is due
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
thats a fill problem
slightly off topic but what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern
log the boring ones
attach the pdf
my vial assayed under label but the purity was fine, which matters more
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem
while im here log the lot number
whats the underfill rate people are actually seeing
how much does sample handling on my end affect the number
how do you separate batch variance from supplier variance
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test it again
lot bought purity assay/label
A-2418 2025-03 99.1% 9.6 / 10mg
A-2601 2025-08 98.7% 9.8 / 10mg
B-0114 2026-01 99.3% 9.4 / 10mg
B-0329 2026-04 98.9% 9.9 / 10mgwhile im here if you are testing to settle an argument you will not settle it with n of 1
a result without a lot number and a purchase date is an anecdote with a pdf attached, not advice obviously