my sheet has 3 lots from ERP with a spread under a point, which is tight
#test-results 2025-10-14
Tuesday42 messages8 participantstimes are UTC
Highlights from this day
- area_percent — a point or two between the certificate and an independent result is inside what two labs disagree by 18:23
- surpass_two — update from 11 months ago: retested the same supplier, result came back better, logged both 19:00
- area_percent — if the vial has been through a bad transit you are testing the transit as much as the supplier, ill dig out the number 21:10
- area_percent — what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern 97.4 against a certificate of 98.1 is fine. the same… 21:11
thats a fill problem
a point or two between the certificate and an independent result is inside what two labs disagree by
👍5👀1💀10
attach the pdf
| 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 |
i told FGP about a result they would not have liked and they did not argue. credit where it is due
Archive lookup: cold_pack_carla first appears in this channel on 2025-05-30.
quantity testing is usually a separate line item and it is the one worth paying for
*PeptideMeter not the other one
anyone tested the same lot twice at different labs
posting my Medutest result on lot G-0641, what do people make of it
a supplier disputing a result is rare here and it has never gone well for the supplier
[edited]update from 11 months ago: retested the same supplier, result came back better, logged both
🎉16❤️1👍3
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
when did you buy it
quick one if you are testing to settle an argument you will not settle it with n of 1, thats just me
is quantity testing available as a separate thing or bundled
chromatogram-overlay.png
1240 × 720 · 357 KB · not retained in the public archive
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
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm, i could be wrong
which lab
weigh the vial before you reconstitute. it costs nothing and catches the common failure
does anyone log the negative results, the boring ones
👍1❤️5
underfill is more common than impurity. if you only test purity you are testing the less likely failure, still working it out
does a bad result on one lot condemn the whole supplier
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
| 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 |
how much does sample handling on my end affect the number
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 my result contradicts the supplier certificate, do i tell them
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
do you test every order or sample it
if the vial has been through a bad transit you are testing the transit as much as the supplier, ill dig out the number
😂3📉6🧊10
what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern
97.4 against a certificate of 98.1 is fine. the same supplier landing low four times in a row is a question
✅11🧪1⚠️1
certificate said 98.1 and the independent came back 98.6, is that a problem
coming back after 4 months with a follow up result, where do i put it
[edited]selection bias
sorry to jump in is it worth testing if the vial has already been through a warm transit
log the lot number
anyone had a result they think was a lab error rather than a bad vial
test it again
thats not great
📉16
the results in this channel skew because people test when they are suspicious. that is selection bias and it is real