. 2017 Nov 7;7:14751. doi: 10.1038/s41598-017-15281-0

Table 3.

Reference gene stability ranking for hPDL experiments on orthodontic tooth movement (compressive orthodontic force vs. untreated control), experiments on periodontitis (Agac, toxins/bacterial lysate vs. untreated control) and pooled/overall experimental conditions as calculated by the algorithms geNorm, NormFinder, comparative ΔCq and BestKeeper.

Rank	Total (of 4 methods)		geNorm		NormFinder			comparative deltaC _q		BestKeeper
Rank	Ranking order	Rank sum	Ranking order	Stability value (M)	Ranking order	Stability value (ρ_ig/σ_i)	Standard error	Ranking order	Stability value (mean SD of mean ∆C_q)	Ranking order	Stability value (r)	SD (+/− C_q)	CV (% C_q)
hPDL untreated + compressive orthodontic force (experiments on orthodontic tooth movement, n = 12)
1.)	RPL22	6	RPL22	0.219	RPL22	0.035	0.027	RPL22	0.232	RNA18S5	0.910	0.259	3.110
2.)	PPIB	11	PPIB	0.232	PPIB	0.072	0.024	PPIB	0.246	YWHAZ	0.887	0.373	1.728
3.)	*TBP*	13	*TBP*	*0.245*	*TBP*	*0.085*	*0.026*	*TBP*	*0.260*	*RPL22*	*0.842*	*0.121*	*0.665*
4.)	RNA18S5	19	RPLP0	0.255	RPLP0	0.110	0.029	RPLP0	0.268	*TBP*	*0.808*	*0.202*	*0.860*
5.)	RPLP0	19	EEF1A1	0.269	EEF1A1	0.131	0.033	EEF1A1	0.282	*PPIB*	*0.756*	*0.187*	*1.128*
6.)	EEF1A1	23	RNA18S5	0.305	RNA18S5	0.154	0.037	RNA18S5	0.311	POLR2A	0.660	0.357	1.681
7.)	YWHAZ	29	GAPDH	0.316	GAPDH	0.182	0.042	GAPDH	0.334	RPLP0	0.419	0.098	0.601
8.)	GAPDH	30	POLR2A	0.346	POLR2A	0.207	0.047	POLR2A	0.373	EEF1A1	0.388	0.114	0.814
9.)	POLR2A	30	YWHAZ	0.385	YWHAZ	0.238	0.053	YWHAZ	0.416	GAPDH	−0.139	0.117	0.776
hPDL untreated + Agac toxins/bacterial lysate (experiments on periodontitis, n = 12)
1.)	PPIB	6	PPIB	0.179	PPIB	0.037	0.022	PPIB	0.189	POLR2A	0.840	0.176	0.836
2.)	TBP	8	TBP	0.186	TBP	0.046	0.021	TBP	0.196	TBP	0.761	0.121	0.518
3.)	POLR2A	14	EEF1A1	0.191	POLR2A	0.085	0.024	EEF1A1	0.196	*PPIB*	*0.717*	*0.099*	*0.602*
4.)	EEF1A1	15	POLR2A	0.212	GAPDH	0.086	0.024	*RPL22*	*0.222*	GAPDH	0.683	0.159	1.044
5.)	GAPDH	22	RPLP0	0.213	EEF1A1	0.086	0.024	RPLP0	0.224	RNA18S5	0.643	0.269	3.261
6.)	*RPL22*	23	*RPL22*	*0.213*	*RPL22*	*0.102*	*0.026*	POLR2A	0.225	EEF1A1	0.641	0.167	1.170
7.)	RPLP0	24	GAPDH	0.216	RPLP0	0.109	0.028	GAPDH	0.226	RPLP0	0.562	0.172	1.049
8.)	RNA18S5	29	RNA18S5	0.339	RNA18S5	0.208	0.046	RNA18S5	0.347	*RPL22*	*0.557*	*0.164*	*0.902*
9.)	YWHAZ	36	YWHAZ	0.399	YWHAZ	0.260	0.057	YWHAZ	0.425	YWHAZ	0.266	0.318	1.488
hPDL pooled/overall (experiments on orthodontic tooth movement and periodontitis n = 18)
1.)	PPIB	6	PPIB	0.241	PPIB	0.062	0.021	PPIB	0.254	RNA18S5	0.781	0.266	3.199
2.)	TBP	8	TBP	0.249	TBP	0.073	0.021	TBP	0.263	TBP	0.751	0.173	0.735
3.)	*RPL22*	14	*RPL22*	*0.250*	*RPL22*	*0.085*	*0.022*	*RPL22*	*0.263*	*PPIB*	*0.699*	*0.158*	*0.955*
4.)	RPLP0	19	RPLP0	0.271	RPLP0	0.122	0.026	RPLP0	0.287	POLR2A	0.638	0.280	1.320
5.)	POLR2A	22	EEF1A1	0.303	EEF1A1	0.161	0.031	EEF1A1	0.313	YWHAZ	0.638	0.381	1.777
6.)	EEF1A1	23	POLR2A	0.317	POLR2A	0.168	0.032	POLR2A	0.340	RPL22	0.596	0.141	0.776
7.)	RNA18S5	23	GAPDH	0.335	RNA18S5	0.182	0.034	RNA18S5	0.350	RPLP0	0.429	0.149	0.913
8.)	YWHAZ	31	RNA18S5	0.341	GAPDH	0.187	0.035	GAPDH	0.353	EEF1A1	0.399	0.181	1.277
9.)	GAPDH	32	YWHAZ	0.440	YWHAZ	0.280	0.049	YWHAZ	0.472	GAPDH	0.206	0.189	1.245

A higher rank denotes lower expression stability C_q = quantification cycle; SD = standard deviation; CV = coefficient of variation; r = Pearson’s correlation coefficient.