Figure 1.

Description of the labeling strategy used in this study. The sequence of the 59mer stem–loop TFO is shown. The 59mer oligonucleotide can form a triple helix by binding to a 15 bp oligopurineoligopyrimidine target sequence, located between 4404 and 4418 bp from the extremity of the phage. A fluorescently labeled fragment made by PCR is digested by a class IIS restriction enzyme in order to produce a sticky end that can be ligated to the 5′-end of the TFO. The restriction site for ApaI is indicated.