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.

24 recordsmedian 99.11 %spec 97.5 %

Laboratory	Reports	Gradient	MS resolution	Median purity %	Published bias (pp)	Bias-adjusted	Method suitability
Janoshik	12	30min	High	99.13	+0.00	99.13	ADEQUATE
PeptideMeter	4 n=4	28min	High	98.61	-0.05	98.66	ADEQUATE
Kestrel	4 n=4	15min	Unit	99.38	+0.24	99.14	ADEQUATE
Nordanalyt	3 n=3	35min	High	98.23	+0.02	98.21	ADEQUATE
Medutest	1 n=1	25min	Unit	98.41	+0.08	—	ADEQUATE
VendorInvestigate	0	32min	High	—	-0.11	—	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.