Cross-section

IGF-1 LR3 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 IGF-1 LR3, with a class minimum gradient of 15 min, the method is a live explanation.

86 recordsmedian 97.75 %spec 95.0 %

Laboratory	Reports	Gradient	MS resolution	Median purity %	Published bias (pp)	Bias-adjusted	Method suitability
Janoshik	46	30min	High	97.75	+0.00	97.75	ADEQUATE
PeptideMeter	18	28min	High	98.25	-0.05	98.30	ADEQUATE
Medutest	11	25min	Unit	97.83	+0.08	97.75	ADEQUATE
VendorInvestigate	9	32min	High	97.29	-0.11	97.40	ADEQUATE
Nordanalyt	1 n=1	35min	High	97.00	+0.02	—	ADEQUATE
Kestrel	1 n=1	15min	Unit	96.83	+0.24	—	ADEQUATE

Figure. IGF-1 LR3 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.