Table 1.

Accuracy and interday precision estimated in standard medium and biological samples

	In IDO1 activity mixture			In cell lysatea
	ʟ-Kyn concentration added (µM)
	0.043	2.15	8.60	0.043b	2.15b	8.60b
Day 1
Mean ± SD (µM)	0.039 ± 0.002	2.193 ± 0.017	8.822 ± 0.070	0.048 ± 0.005	2.428 ± 0.008	9.524 ± 0.029
RSD (%)	6.16	0.76	0.79	5.31	0.32	0.31
Accuracy (%)	90.60	101.98	103.74	112.67	112.95	110.74
Day 2
Mean ± SD (µM)	0.040 ± 0.003	2.034 ± 0.007	8.586 ± 0.026	0.043 ± 0.010	1.982 ± 0.013	8.204 ± 0.023
RSD (%)	8.07	0.34	0.30	2.03	0.53	0.33
Accuracy (%)	93.27	94.59	99.84	111.03	89.92	95.40
Day 3
Mean ± SD (µM)	0.039 ± 0.002	1.996 ± 0.007	8.256 ± 0.021	0.040 ± 0.006	2.102 ± 0.181	8.936 ± 0.353
RSD (%)	5.03	0.37	0.26	6.53	8.41	3.93
Accuracy (%)	90.39	92.84	96.00	91.94	97.77	103.91

^aCell lysate from MDA-MB-231 cancer cells; ^bcalculated as follows: ʟ-Kyn concentration in spiked sample (µM) – ʟ-Kyn concentration in blank sample (µM).

Standard deviation (SD) values were calculated from 6 measurements.