Table 3. CP data of housekeeping genes by BestKeeper.

No.	18s		CycA		36B4		GAPDH		HPRT		ActB		U6
	Cn	SIDR	Cn	SIDR	Cn	SIDR	Cn	SIDR	Cn	SIDR	Cn	SIDR	Cn	SIDR
Geometric mean (CP)	16.65	16.63	29.98	30.25	27.45	27.50	31.04	31.36	26.41	26.30	16.83	17.42	25.15	25.82
Arithmetic mean (CP)	16.65	16.54	29.99	30.28	27.45	27.51	31.05	31.36	26.41	26.30	16.88	17.43	25.18	25.83
Min (CP)	15.80	16.00	29.30	28.50	27.10	26.40	29.30	30.40	26.00	24.60	15.50	16.80	23.40	24.80
Max (CP)	17.10	17.00	30.90	32.30	27.90	28.80	31.80	32.20	26.80	27.00	19.80	18.30	26.30	26.80
SD (±CP)	0.26	0.29	0.41	0.97	0.25	0.54	0.57	0.40	0.29	0.43	0.99	0.36	0.88	0.38
CV (% CP)	1.58	1.74	1.38	3.20	0.91	1.98	1.85	1.27	1.09	1.62	5.89	2.04	3.50	1.48
Min (x-fold)	-1.80	-1.45	-1.61	-3.37	-1.27	-2.15	-3.34	-1.94	-1.33	-1.62	-2.51	-1.54	-3.37	-2.03
Max (x-fold)	1.37	1.38	1.89	4.14	1.37	2.46	1.69	1.79	1.31	1.63	7.85	1.84	2.21	1.97
SD (±x-fold)	1.20	1.22	1.33	1.96	1.19	1.46	1.49	1.32	1.22	1.34	1.99	1.28	1.84	1.30

Descriptive statistics of seven candidate housekeeping genes based on their CP scores. n: Number of samples; CP: Crossing point; SD (±CP): Standard deviation of the CP; CV (%CP): Coefficient of variance expressed as a percentage on the CP level; Min (x-fold) and Max (x-fold): Extreme values of expression levels expressed as an absolute x-fold over- or under-regulation coefficient; SD (±x-fold): Standard deviation of the absolute regulation coefficients; Cn: Control; SIDR: Streptozotocin-induced diabetic rats; 18s: 18s ribosomal unit 5; CycA: Cyclophilin A; 36B4: Ribosomal protein large P0; GAPDH: Glyceraldehyde-3-phosphate dehydrogenase; HPRT: Hypoxanthine-guanine phosphoribosyl transferase; ActB: Beta-actin; U6: Terminal uridylyl transferase 1.

n=8