if you are testing to settle an argument you will not settle it with n of 1
#test-results 2025-04-30
Wednesday33 messages8 participantstimes are UTC
Highlights from this day
- HPLC_Hank — my sheet has 8 lots from SSA with a spread under a point, which is tight 09:24
- VialBot — Channel stats, last 30 days: 38 messages from 43 members. 11:07
- maintenance_mo — unrelated but my vial assayed under label but the purity was fine, which matters more 11:19
- ferrous_ash — sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm a result without a lot number and a purchase date is an anecdote… 12:39
- bpc_sceptic — assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem 16:19
posting my PeptideMeter result on lot SG-1177, what do people make of it
i test roughly every tenth vial. it is a sampling strategy, not paranoia
thats a fill problem
my sheet has 8 lots from SSA with a spread under a point, which is tight
🔥4⚠️6
when did you buy it
do the results in this channel skew because people test when suspicious
nice result
📈16🤝1❤️18
a result without a lot number and a purchase date is an anecdote with a pdf attached
whats the worst result anyone has logged and what happened next
99 against a certificate of 96.8 is fine. the same supplier landing low four times in a row is a question
underfill is more common than impurity. if you only test purity you are testing the less likely failure
Channel stats, last 30 days: 38 messages from 43 members.
🙏1
unrelated but my vial assayed under label but the purity was fine, which matters more
🔥8
if the vial has been through a bad transit you are testing the transit as much as the supplier
thats not great
a single sample tells you about a single vial. that is genuinely all it tells you
log the boring ones
sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm
a result without a lot number and a purchase date is an anecdote with a pdf attached
a supplier disputing a result is rare here and it has never gone well for the supplier
test it again
how many lots do you need before you can say anything about a supplier
my result contradicts the supplier certificate, do i tell them
has a supplier ever disputed a result posted here
the widest spread in my data is about 2.6 percentage points across five lots from one supplier, i have it written down somewhere
is it worth testing if the vial has already been through a warm transit
post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem
🤝2
i have never regretted spending the money on a test. i have regretted not testing twice
right so weigh the vial before you reconstitute. it costs nothing and catches the common failure
is quantity testing available as a separate thing or bundled
ok so the results in this channel skew because people test when they are suspicious. that is selection bias and it is real
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ