Cross-section

Kisspeptin-10 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 Kisspeptin-10, with a class minimum gradient of 22 min, the method is a live explanation.

70 recordsmedian 99.27 %spec 98.5 %

Laboratory	Reports	Gradient	MS resolution	Median purity %	Published bias (pp)	Bias-adjusted	Method suitability
Janoshik	36	30min	High	99.25	+0.00	99.25	ADEQUATE
PeptideMeter	10	28min	High	99.34	-0.05	99.39	ADEQUATE
Medutest	9	25min	Unit	98.53	+0.08	98.45	ADEQUATE
Nordanalyt	6 n=6	35min	High	99.75	+0.02	99.73	ADEQUATE
VendorInvestigate	5 n=5	32min	High	99.09	-0.11	99.20	ADEQUATE
Kestrel	4 n=4	15min	Unit	99.17	+0.24	98.94	BELOW CLASS MINIMUM

Figure. Kisspeptin-10 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.