Table 2.

Within-run and within-laboratory imprecision.

	Magnesium (µM)
	Low	Intermediate	High
Within-Run a
Mean	561	799	1222
SD	8	6	11
%CV	1.5	0.7	0.9
Within-Laboratory b
Mean	567	762	1179
SD	25	36	50
%CV	4.5	4.7	4.2

^a Based on 1 run of 20 tests (n = 20), ^b Based on 2 runs per day in duplicate for 20 days (n = 80).