is it worth testing if the vial has already been through a warm transit
🔥3
#test-results 2025-11-04
Tuesday42 messages11 participantstimes are UTC
Highlights from this day
- two_four_ceiling — assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem, ask me again in a month 22:16
- assay_not_purity — a single sample tells you about a single vial. that is genuinely all it tells you 22:27
- ghent_gradient — whats the underfill rate people are actually seeing 22:34
- ghent_gradient — update from 24 months ago: retested the same supplier, result came back better, logged both, i think 22:36
- vat_on_import — my sheet has 2 lots from HJ with a spread under a point, which is tight 23:27
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem, ask me again in a month
🧪1❤️5💀10
log the lot number
one data point
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
i have never regretted spending the money on a test. i have regretted not testing twice
if the vial has been through a bad transit you are testing the transit as much as the supplier
[edited]a single sample tells you about a single vial. that is genuinely all it tells you
📉11
my vial assayed under label but the purity was fine, which matters more
does a bad result on one lot condemn the whole supplier
quick one if you are testing to settle an argument you will not settle it with n of 1
whats the underfill rate people are actually seeing
✅5🧪1🔥10
update from 24 months ago: retested the same supplier, result came back better, logged both, i think
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 / 10mgupdate on the earlier thing post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
whats the lot
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 / 10mgwhen did you buy it
| 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 |
update on the earlier thing a result without a lot number and a purchase date is an anecdote with a pdf attached, i have it written down somewhere
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
underfill is more common than impurity. if you only test purity you are testing the less likely failure
🔥4
a point or two between the certificate and an independent result is inside what two labs disagree by
thats within range
is anyone tracking results over time in a way they would share
🎉2❤️1
selection bias
weigh it first
👍2🧪12
what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern
do the results in this channel skew because people test when suspicious
chromatogram-overlay.png
1240 × 720 · 239 KB · not retained in the public archive
thats a fill problem
nice result
does anyone log the negative results, the boring ones
weigh the vial before you reconstitute. it costs nothing and catches the common failure, take that with a pinch of salt
is quantity testing available as a separate thing or bundled
posting my VendorInvestigate result on lot A-2418, what do people make of it
log the boring results too. a channel that only records failures produces a false picture, n of 1 obviously
🧊6
whats the worst result anyone has logged and what happened next
thats not great
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
i test roughly every tenth vial. it is a sampling strategy, not paranoia
my sheet has 2 lots from HJ with a spread under a point, which is tight
🔥1📉3
coming back after 14 months with a follow up result, where do i put it
attach the pdf
test it again
which lab