if the vial has been through a bad transit you are testing the transit as much as the supplier
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#test-results 2025-11-06
Thursday45 messages12 participantstimes are UTC
Highlights from this day
- LC_MS_Lena — if you are testing to settle an argument you will not settle it with n of 1 11:59
- related_subs — weigh the vial before you reconstitute. it costs nothing and catches the common failure 12:54
- sgp_subq — do you test every order or sample it 14:22
- retention_time — does anyone log the negative results, the boring ones 14:40
- VialBot — Assay note: SWB lot H-2814 reported at 96.8% of label content. 15:15
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem
the results in this channel skew because people test when they are suspicious. that is selection bias and it is real
how many lots do you need before you can say anything about a supplier
right so i have never regretted spending the money on a test. i have regretted not testing twice
while im here my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
if you are testing to settle an argument you will not settle it with n of 1
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coming back to this coming back after 4 months with a follow up result, where do i put it
thats a fill problem
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
a supplier disputing a result is rare here and it has never gone well for the supplier
weigh the vial before you reconstitute. it costs nothing and catches the common 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 / 10mg🎉5📉2👀6
my vial assayed under label but the purity was fine, which matters more
attach the pdf
i told JEEP about a result they would not have liked and they did not argue. credit where it is due
how much does sample handling on my end affect the number
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post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
when did you buy it
anyone tested the same lot twice at different labs
weigh it first
the widest spread in my data is about 2.6 percentage points across five lots from one supplier, from memory
log the boring results too. a channel that only records failures produces a false picture
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a single sample tells you about a single vial. that is genuinely all it tells you
for the archive a result without a lot number and a purchase date is an anecdote with a pdf attached
do you test every order or sample it
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 / 10mgnice result
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quantity testing is usually a separate line item and it is the one worth paying for
does anyone log the negative results, the boring ones
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does a bad result on one lot condemn the whole supplier
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which lab
whats the lot
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Archive lookup: retention_time first appears in this channel on 2025-05-22.
what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern
99.2 against a certificate of 96.8 is fine. the same supplier landing low four times in a row is a question
Assay note: SWB lot H-2814 reported at 96.8% of label content.
Purity check: no report on file for lot D-0718. Nothing logged either way.
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
one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
how do you separate batch variance from supplier variance
one data point
[edited]ok so my sheet has 8 lots from WXT with a spread under a point, which is tight
log the lot number
selection bias
follow up i had a result i am fairly sure was a handling error on my side and i logged it as such
has a supplier ever disputed a result posted here