[Lab] 5th independent test on HJ — 99.2% on a claimed 99.0%, and the trend is the interesting part
Title says it — 5th independent test on HJ — 99.2% on a claimed 99.0%, and the trend is the interesting part — so here is the boring supporting detail that makes it worth anything.
The relevant figures are 99.2% and 99.0%, and they come from the same log I have kept the whole time.
Tested three lots over a year rather than three vials from one lot. Cost the same and told me something completely different.
First result I ever posted here got asked for the batch number and the claim. Fair, and my posts have been better ever since.
Research-use-only material is not approved for human use and nothing here should be read as a recommendation to use it.
- HJHJ source pageHubei Jianxiang Bioscience Co., Ltd. · Xianning · 92% here, rank 13 · shop at hubeijianxiang.net →
nofollow and sponsored; nobody here is paid for it.best — the order this archive was captured in
A series across separate lots estimates a process. Repeat tests on one lot estimate the measurement. Both are useful and they answer different questions.
Push back: three tests on one lot is one lot. It tells you about that lot and almost nothing about the next one.
Is that the same lot as the one in the thread from last month?
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if you are going to test, test the thing you actually received
A series across separate lots estimates a process.
This is why the template has a batch field. Without it the result is about a vial nobody can identify.
Yes. Two services on the same batch is the strongest thing an individual member can produce, and it is not expensive.
split a vial across two services once and you will never argue about ground truth again
split a vial across two services once and you will never argue about ground truth again
Disagreeing with this line: that gap is ordinary variance, not a contradiction between the lab and the certificate.
Small fix — same supplier, different lot. The two rows in the log are not the same batch.
Right, and a point or two between services is ordinary. It is agreement, and every month somebody posts it as a scandal.
Kept every report as a PDF with the batch in the filename. Two years in, it is the most useful folder I own.
Yes — date of analysis, because a result from two years ago describes a different manufacturing month.
GL Biochem came back 99.3% on a claimed 99.0%, which is agreement not a discrepancy
a result with no batch number is about a vial nobody can identify
Not convinced by the comparison. Different services, different gradients, and you are treating one as ground truth.
How to build a series that means something, if you are going to spend money on testing anyway.
Three tests on one lot tells you about your measurement. Three tests on three lots, spread over a year, tells you about a process. The second is the one worth paying for and it costs the same.
Buy small, keep the batch numbers, send one vial per lot, and post each one with the claim next to it. After four or five you have something no individual review can give you: a band, a direction and a date range. That is what the source pages are made of.
Correction: that is the claimed figure, and the measured one is the higher of the two in your own screenshot.
Split one vial between Medutest and PeptideMeter. The two numbers were within half a point of each other and I stopped worrying about which lab to trust.
Merged with the other thread on the same batch so the results sit together.
Agreed on quoting the claim alongside the result. Half the arguments here are two people comparing to different reference numbers.
Disagree that this is a discrepancy. 99.4% against a claimed 99.0% is inside ordinary inter-lab variance in either direction.
That service reports area percent by default. Worth stating, since the thread has been comparing it to a mass figure.
Sent a vial in specifically to check a supplier’s claim after a good experience. It matched. Boring result, worth logging.
the trend across lots is worth more than any single figure
GGPeps BPC, batch matched the paperwork, VendorInvestigate came back 99.6% against a claimed 99.0%. Paid for it myself, posting it because the log is only worth anything if people do.
date of analysis matters as much as the number
Careful with the trend claim. Four results over two years is a very sparse series to draw a line through.
Which service, and did you pay for it yourself?
one result is a data point, agreement between two services is evidence
- 1A series across separate lots estimates a process. Repeat tests on one lot…11 comments in this branch · started by u/bpc_sceptic
- 2Kept every report as a PDF with the batch in the filename. Two years in, it…7 comments in this branch · started by u/yusuf_kirchner