Table 2. RNA purity, yield, and integrity.

Sample conditions	A260/A280	RNA yield (µg)	RIN
RNA extraction immediately after venipuncture
Ctrl 1	1.96±0.06	2.91±1.44	9.56±0.22
Ctrl 2	1.96±0.07	3.00±1.51	9.59±0.25
RNA extraction after freezing for over 24 h
Without stab	1.97±0.06	2.93±1.16	8.44±1.00**
Later	1.60±0.14***	0.31±0.08$ ,**	N.A.
Protect	1.92±0.05**	2.06±0.63	7.66±0.33***
Lock	1.99±0.04*	1.73±0.62*	9.57±0.31
Shield	1.87±0.10***	0.93±0.53# ,**	N.A.
Stab	2.02±0.04***	2.91±1.29	9.45±0.65
SDS	1.97±0.05	2.14±0.97*	5.93±1.93***
1-Thio	1.99±0.04**	2.56±0.98	9.74±0.17*

RNA purity, yield, and integrity were measured for 11 individual samples. A260/A280 indicates the ratio of absorbance at 260 and 280 nm.

N.A.: not available (not measureable), RIN: RNA integrity number.

*p<0.05; **p<0.01; ***p<0.001 (Wilcoxon signed rank test).

^$RNA yield could be measured for nine individual samples (failed in two samples).

^#RNA yield could be measured for 10 individual samples (failed in one sample).