Figure 2.

Triplex DNA formation by non-conjugated and daunomycin-conjugated TFOs. Oligonucleotides corresponding to the pyrimidine-rich strands of the duplex targets were 5′ end-labeled with [γ-³²P]ATP and annealed to the complementary oligonucleotides. Duplex DNA at a concentration of 1 nM was incubated for 18 h at 37°C with the indicated concentrations of non-conjugated GT11, dauno-GT11 or dauno-CO11. Gel electrophoresis was carried out under non-denaturating conditions at a gel temperature of 20 (A, B, D, E and F) or 10°C (C). Duplex targets were the 28 (A–D), 23 (E) and 40 bp (F) double-stranded oligonucleotides (see Fig. 1). Positions of duplex and triplex DNA are indicated.