if you are testing to settle an argument you will not settle it with n of 1
#test-results 2024-07-28
Sunday36 messages10 participantstimes are UTC
Highlights from this day
- slow.taper — if the vial has been through a bad transit you are testing the transit as much as the supplier, i think 20:17
- area_percent — unrelated but i had a result i am fairly sure was a handling error on my side and i logged it as such 20:40
- belfast_bac — a result without a lot number and a purchase date is an anecdote with a pdf attached 20:52
- belfast_bac — while im here my vial assayed under label but the purity was fine, which matters more 21:16
- belfast_bac — underfill is more common than impurity. if you only test purity you are testing the less likely failure 21:18
do the results in this channel skew because people test when suspicious
how much does sample handling on my end affect the number
log the lot number
is a purity-only test worth the money if underfill is the common failure
post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
[edited]my sheet has 5 lots from CPC with a spread under a point, which is tight
📉1
if the vial has been through a bad transit you are testing the transit as much as the supplier, i think
| 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 |
thats not great
a point or two between the certificate and an independent result is inside what two labs disagree by, your mileage will differ
the widest spread in my data is about 2.6 percentage points across five lots from one supplier
a supplier disputing a result is rare here and it has never gone well for the supplier
has a supplier ever disputed a result posted here
how do you post a result so it is actually useful to somebody in a year
unrelated but i had a result i am fairly sure was a handling error on my side and i logged it as such
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 / 10mg🎉14⚠️6
Recon calculator: 20mg in 1ml = 4mg/ml.
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whats the worst result anyone has logged and what happened next
weigh it first
does anyone log the negative results, the boring ones
a result without a lot number and a purchase date is an anecdote with a pdf attached
| 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 do you separate batch variance from supplier variance
[edited]thats a fill problem
while im here my vial assayed under label but the purity was fine, which matters more
🎉10
underfill is more common than impurity. if you only test purity you are testing the less likely failure
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 / 10mgsample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
quantity testing is usually a separate line item and it is the one worth paying for, ask me again in a month
how many lots do you need before you can say anything about a supplier
do you test every order or sample it
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
when did you buy it
anyone tested the same lot twice at different labs
certificate said 98.6 and the independent came back 98.1, is that a problem
attach the pdf
one data point
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ, anyway
update from 3 months ago: retested the same supplier, result came back better, logged both