Medutest — 8 things I got wrong before I got it right
Medutest — 8 things I got wrong before I got it right, and I am aware this is a minority view on this board.
What a result posted here is actually worth, and how to make yours worth more.
A single figure with no batch identifier is about a vial nobody can locate. Add the batch and it becomes about a lot. Add the claimed figure from the certificate and it becomes a comparison. Add the service and the date and it becomes reproducible. Say that you paid for it yourself and it becomes independent.
Five extra fields, thirty seconds of typing, and the difference between a comment and a row in the log that will still be useful in three years.
On inter-lab disagreement, which generates more heat here than anything else.
Two services running different gradients, integrating differently, at possibly different wavelengths, will not produce identical numbers on the same material. A point either way is ordinary. Half a point is close agreement.
The productive response to a gap that size is to post both results with both methods and let the log accumulate. The unproductive response is to pick the lower number, call it the truth, and open a dispute. Members have done the first for long enough now that the bands in the vendor tables are genuinely informative.
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.
Tell me where this is wrong. That is the useful part of posting it.
best — the order this archive was captured in
Area percent and net peptide content are different measurements and most reports give one. Quote which, or the comparison downstream is meaningless.
The template is vendor, compound, batch, service, claim, result, and who paid. Every one of those fields exists because a result missing it has been argued about here before.
The template is vendor, compound, batch, service, claim, result, and who paid.
This is why the template has a batch field. Without it the result is about a vial nobody can identify.
Yes — date of analysis, because a result from two years ago describes a different manufacturing month.
Cosigning on saying who paid. It is the whole basis on which this log is worth anything.
if you are going to test, test the thing you actually received
results without method are gossip with decimals
Batch number and date of analysis?
net peptide content if the report gives it, and say which you are quoting
A series across separate lots estimates a process. Repeat tests on one lot estimate the measurement. Both are useful and they answer different questions.
What was the claim on the certificate you are comparing against?
A series across separate lots estimates a process.
anders_vermeulen is right that the band matters more than the peak. Consistency across lots is the finding.
anders_vermeulen is right that the band matters more than the peak.
Disagreeing with this line: that gap is ordinary variance, not a contradiction between the lab and the certificate.
date of analysis matters as much as the number
inter-lab variance runs a point or two, plan your outrage accordingly
First result I ever posted here got asked for the batch number and the claim. Fair, and my posts have been better ever since.
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the trend across lots is worth more than any single figure
Kept every report as a PDF with the batch in the filename. Two years in, it is the most useful folder I own.
- 1A series across separate lots estimates a process. Repeat tests on one lot…10 comments in this branch · started by u/anders_vermeulen