Table 1.

Effects of regular intervals and reaction duration on the integration strategy

Condition	Method	Equation	Upper limit (U/L)	Lower limit (U/L)
RD=6 min dt=10 s	Classical initial rate method	Vi=0.217x+0.879, s<0.15	11.0	0.45
	Improved integrated method	Vi=0.215x+0.889, s<0.21	32.0	~9.0*
	Integration strategy	Vi=0.216x+0.788, s<0.29	32.0	0.87
RD=6 min dt=20 s	Classical initial rate method	Vi=0.214x+0.920, s<0.17	10.0	0.51
	Improved integrated method	Vi=0.213x+0.933, s<0.21	32.0	~10.0*
	Integration strategy	Not available
RD=8 min dt=10 s	Classical initial rate method	Vi=0.217x+0.879, s<0.16	11.0	0.48
	Improved integrated method	Vi=0.215x+0.852, s<0.20	32.0	~9.0*
	Integration strategy	Vi=0.215x+0.738, s<0.20	32.0	0.93
RD=8 min dt=20 s	Classical initial rate method	Vi=0.211x+1.120, s<0.17	10.0	0.51
	Improved integrated method	Vi=0.213x+0.939, s<0.23	32.0	~9.0*
	Integration strategy	Vi=0.214x+0.930, s<0.30	32.0	0.90
RD=8 min dt=30 s	Classical initial rate method	Vi=0.208x+1.080, s<0.21	9.0	0.63
	Improved integrated method	Vi=0.204x+1.470, s<0.24	32.0	~10.0*
	Integration strategy	Not available

The same series of reaction curves were analyzed after adjusting the regular intervals and/or the reaction duration. All linear response equations gave R ²>0.99

^*indicated the detection limit was higher than the lower limit and hence the detection limit itself was used as the lower limit

RD: reaction duration; dt: regular interval; V _i: initial rate; x: amount of GGT from kidney homogenate