Analysis of PCR products obtained in the detection of 5′-cap structures in viral RNAs by the ‘cap-jumping’ method with the use of the following templates: RNA-tagged genomic TMV RNA (U1 strain) (lanes 1 and 2), RNA-tagged uncapped RNA transcript of the complete cDNA clone of TMV (lanes 3 and 4), the complete cDNA clone of TMV (lane 5), RNA-tagged genomic crTMV RNA (lanes 6, and 7), RNA-tagged uncapped RNA transcript of the complete cDNA clone of crTMV (lanes 8 and 9), the complete cDNA clone of crTMV (lane 10), RNA-tagged genomic crTMV RNA in total RNA of crTMV-infected tobacco (ribosome fraction) (lanes 11 and 12). M, molecular markers.