Figure 3.

(A) Temperature dependence of the fluorescence emission of 2AP, incorporated in the oligonucleotides: R^aCW (open circles), RCW^a (squares), CW^2AP (diamonds) and R^addCW (open triangles). Every 10th experimental point is marked. The excitation wavelength was 310 nm, emission was measured at 370 nm. Samples contained 1 µM oligonucleotides, 0.5 M LiCl and 10 mM Tris–HCl buffer, pH 7.6. Note: comparison between 2AP in the duplex and in the third strand of the triplex. (B) Temperature dependence of the fluorescence emission of 2AP incorporated in the R^aCW at different concentrations of the oligonucleotide: 1 µM (open circles), 50 µM (filled triangles). The fluorescence was measured in 3 and 1.5 mm cells, respectively.