. 2018 Jul 19;13(7):e0201069. doi: 10.1371/journal.pone.0201069

Table 1. Comparison of two centrifugation protocols to produce platelet-poor plasma.

	Centrifugation	n	Normalized to cel-miR-39			Normalized to miR-16			Normalized to mean of cel-miR-39 and miR-16
	Centrifugation	n	Mean	CV (%)	P-value	Mean	CV (%)	P-value	Mean	CV (%)	P-value
miR-92a	Single	15	9.9	19.5	0.35	0.095	11.3	0.83	0.97	13.1	0.52
miR-92a	Dual	15	9.2	21.1	0.35	0.096	9.5	0.83	0.94	13.3	0.52
miR-126	Single	15	0.28	10.9	0.26	0.0027	14.0	0.01	0.027	9.2	0.02
miR-126	Dual	15	0.30	17.3	0.26	0.0031	14.2	0.01	0.030	12.5	0.02
miR-16	Single	15	105	19.0	0.25
miR-16	Dual	15	96	19.4	0.25

30 tubes of EDTA-anticoagulated whole blood were drawn from a peripheral vein of a healthy volunteer. From each tube platelet-poor plasma (PPP) was prepared by either dual centrifugation or a prolonged single step centrifugation. MicroRNA-levels in each PPP were measured using RT-qPCR (single assays) and normalized to either cel-miR-39, miR-16 or the mean of cel-miR-39 and miR-16. For each centrifugation protocol and with all normalization strategies, the mean relative microRNA level and the coefficient of variation (CV) are provided. P-values (t-test) are shown for the comparison of the mean of the two centrifugation protocols.