Figure 2.

The stability of miRNAs in plasma. Aliquots of two clinical patient plasma samples were subjected to up to six cycles of freeze-thaw (A) or incubated at 4°C (B) or 37°C (C) for up to 48 h, or digested with addition of different concentrations of RNase A (D). Then miRNAs were extracted and miR-155 was quantified with qRT-PCR. Data was shown in Ct value. E-F, Pools of extracted total RNA from samples of lung cancer patients (E) and normal controls (F) were subjected to incubation in 37 °C for 2 h with or without RNase A digestion. The levels of miR-155, miR-21 and miR-197 were determined and the data was shown as relative level of miRNAs normalized with the original level.