FIGURE 1.

Long-term storage study design to evaluate RNA integrity and quality of samples collected in K₂EDTA or Tempus™ blood tubes that have been kept at −80°C. Ideal situation: GJ_fresh: collected using a K₂EDTA tube, incubated at 4°C (for up to 4 h), and extracted using the GeneJET protocol; Temp: collected/stored/extracted following the standard Tempus™ protocol; GJ_aliq: collected using a K₂EDTA tube; a 250-µL aliquot is taken and stored in a 1.5-mL Microcentrifuge tube (according to manufacturer instructions) and then thawed with 250 µl of kit buffer and extracted using the GeneJET protocol. Real situation: EDTA + Temp: collected/stored using a K₂EDTA tube, stored at −80°C, and thawed on ice; then 3 mL of whole blood was pipetted into a Tempus™ tube, vigorously shaken for 10 s, incubated at RT (∼3 h), and then extracted using the Tempus protocol; EDTA + GJ: collected/stored using a K₂EDTA tube, stored at –80°C, and thawed on ice; next, 250 µl of whole blood was pipetted into a 1.5-mL Microcentrifuge tube and then extracted using the GeneJET protocol.