Table 1. Error rates during sample exchanges (a) without consideration of the inclination of the cassette, (b) with consideration of the inclination of the cassette, (c) after the modification based on the height difference between the strong end and the weak end of the dumbbell magnet tool.

	Trials	Errors	Error rate (%)
(a)	634	47	7.4
(b)	4234	114	2.7
(c)	3840	1	0.026