PCR and RT-PCR results from density gradient band. (A) Electrophoresis gel showing PCR and RT-PCR results using primers for Probe 1 (397 bp), Probe 2 (642 bp) and Probe 3 (399 bp) to carry out PCR and RT-PCR reactions with total nucleic acid template extracted from the 21% CsCl band. Lanes 1-6: PCR reactions carried out using template treated with DNase (Lanes 1-3) and RNase (Lanes 4-6) and showing none of the expected amplicons. Lanes 7-12: RT-PCR reactions (Probes 1-3 sequentially) carried out using template treated with DNase (Lanes 7-9) and RNase (Lanes 10-12) and showing amplicons with DNase treatment but not RNase treatment, indicating that the ICE amplicons originated from RNA. Lanes +C, +M and +B = Positive controls for Probes 1 to 3, respectively. Lanes M = DNA ladder marker. (B) Electrophoresis gel showing the predicted 1958 bp amplicon obtained using the forward primer of Probe 1 and the reverse primer of Probe 3.