Table 1. Plasma ccfDNA concentrations detected in 30 individuals at time point of blood collection (t = 0), after storage of 24 and 48 h at RT and 4 - 8 °C.

N = 30	Storage	ccfDNA (ng/mL)	Difference (%)	P
Tube 1	t = 0	3.17 (2.13 – 3.76)	/	/
Tube 2	24 h / RT	3.02 (2.41 – 3.68)	- 4.73	0.975
Tube 3	24 h / 4-8°C	3.21 (2.19 – 3.46)	+ 1.26	0.387
Tube 4	48 h / RT	3.13 (2.10 – 3.76)	- 1.26	0.102
Tube 5	48 h / 4-8°C	3.09 (2.19 – 3.50)	- 2.52	0.465
ccfDNA – circulating cell-free DNA. t = 0 – time point of blood sample collection. h – hours. RT – room temperature. Differences of ccfDNA concentrations observed for various storage conditions were evaluated using the Wilcoxon test. Data are presented as median (Q1 – Q3). P < 0.05 was considered statistically significant.