Table 1.

Intra- and interday accuracy and precision

	Nominal concentrations (ng/mL)	Mean calculated concentrations (ng/mL)	Accuracy (bias %)	Precision (% CV)
OS
Intraday (n = 3)	75	70.6	−5.9	4.7
	150	159.6	6.4	1.8
Interday (n = 3)	75	72.2	−3.7	6.5
	150	151.0	0.7	8.7
OSC
Intraday (n = 3)	75	78.5	4.6	4.5
	200	219.3	9.7	1.0
	750	686.3	−8.5	1.4
Interday (n = 3)	75	74.7	−0.5	7.3
	200	221.1	10.5	0.8
	750	708.5	−5.5	4.4

Intra- and interday accuracy and precision measurements of three independent measurements of the respective QC samples for OS and OSC, n = 4. The accuracy is expressed as the bias of the measurement and the precision as % CV