After the addition of 1–3mL of RNA sample and Taq polymerase,
PCR tubes were placed in a thermocycler (GenAmp PCR System
9700). The RT-PCR cycle included incubation at 45 C for 60 min,
followed by a preheating step of 7 min at 95 C, then 40 cycles of
45 s at 94 C, 45 s at 50–55 C and 60 s at 72 C, and a final extension
step at 72 C for 5 min. Following PCR, 10–20% of the product was
added to 1–2mL of loading dye (Bromphenol-blue dan Cyline
Cyanol) and subjected to electrophoresis in 1% agarose. The gel was
stained with 25mg/mL ethidium bromide and visualized under UV
light.