Cross-section

Thymosin α1 by laboratory

The same compound measured by different laboratories on different gradients. Where the medians differ, the question is whether the material differed or the method did — and for Thymosin α1, with a class minimum gradient of 15 min, the method is a live explanation.

43 recordsmedian 99.40 %spec 97.5 %

Laboratory	Reports	Gradient	MS resolution	Median purity %	Published bias (pp)	Bias-adjusted	Method suitability
Janoshik	16	30min	High	99.42	+0.00	99.42	ADEQUATE
PeptideMeter	14	28min	High	99.19	-0.05	99.24	ADEQUATE
VendorInvestigate	5 n=5	32min	High	99.81	-0.11	99.92	ADEQUATE
Medutest	3 n=3	25min	Unit	99.54	+0.08	99.46	ADEQUATE
Kestrel	3 n=3	15min	Unit	99.52	+0.24	99.28	ADEQUATE
Nordanalyt	2 n=2	35min	High	99.08, 98.58	+0.02	—	ADEQUATE

Figure. Thymosin α1 purity by contributing laboratory. Any offset between rows has two possible sources — a real difference in the material each laboratory happened to receive, and the laboratory's own bias — and this figure cannot separate them. The paired analysis that can is on inter-lab agreement.