how do you post a result so it is actually useful to somebody in a year
fridge-thermometer.png
800 × 800 · 812 KB · not retained in the public archive
#test-results 2025-09-11
Thursday40 messages11 participantstimes are UTC
Highlights from this day
- area_percent — do you test every order or sample it 20:42
- ten_of_ten — sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm 21:27
- batch_bandit — certificate said 98.6 and the independent came back 98.1, is that a problem 21:44
- lean_mass_lex — i told GL Biochem about a result they would not have liked and they did not argue. credit where it is due, from memory 21:51
a single sample tells you about a single vial. that is genuinely all it tells you
i had a result i am fairly sure was a handling error on my side and i logged it as such
update on the earlier thing the results in this channel skew because people test when they are suspicious. that is selection bias and it is real
genuine question update from 21 months ago: retested the same supplier, result came back better, logged both
whats the worst result anyone has logged and what happened next
do you test every order or sample it
fridge-thermometer.png
800 × 800 · 409 KB · not retained in the public archive
🧊6💀3✅14
unrelated but the honest limits: hobby chain of custody is weak and any result here should be read with that in mind
selection bias
a supplier disputing a result is rare here and it has never gone well for the supplier, we shall see
[edited]anyone had a result they think was a lab error rather than a bad vial
my sheet has 3 lots from MKM with a spread under a point, which is tight
whats the lot
whats the underfill rate people are actually seeing
attach the pdf
chromatogram-overlay.png
1240 × 720 · 709 KB · not retained in the public archive
does anyone log the negative results, the boring ones
what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern
genuine question a point or two between the certificate and an independent result is inside what two labs disagree by
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
[edited]✅10🧊11🤝1
sorry to jump in how many lots do you need before you can say anything about a supplier
anyone tested the same lot twice at different labs
✅1👀1
weigh the vial before you reconstitute. it costs nothing and catches the common failure
certificate said 98.6 and the independent came back 98.1, is that a problem
🤝1🔥17😂2
i told GL Biochem about a result they would not have liked and they did not argue. credit where it is due, from memory
🙏13
96.8 against a certificate of 97.4 is fine. the same supplier landing low four times in a row is a question
quantity testing is usually a separate line item and it is the one worth paying for
thats a fill problem
[edited]quantity testing is usually a separate line item and it is the one worth paying for, still working it out
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
if you are testing to settle an argument you will not settle it with n of 1
Inter-lab diff for lot C-4402: 98.1% vs 99.2%. Within expected range.
posting my VendorInvestigate result on lot A-2601, what do people make of it
coming back after 26 months with a follow up result, where do i put it
🔥1✅5
the widest spread in my data is about 2.6 percentage points across five lots from one supplier
[edited]do the results in this channel skew because people test when suspicious
how do you separate batch variance from supplier variance
🧊5🔥17👍15
post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
🧪13
i have never regretted spending the money on a test. i have regretted not testing twice
[edited]