Circular dichroism measurements of nCAp, nTGp and nCGp polycondensation reactions. (A) CD spectrum of single non self-complementary dinucleotides at 8°C. nCAp 10 mM in 0.1 M HEPES buffer (red dashed line) and after 48 h of reaction in 0.4 M EDC in 0.1 M HEPES buffer (red solid line). nTGp 10 mM in 0.1 M HEPES buffer (black dashed line) and after 48 h of reaction in 0.4 M EDC in 0.1 M HEPES buffer (black solid line). (B) nCAp 5 mM with nTGp 5 mM in 0.1 M HEPES buffer pH 7.5 (red line) and in 0.4 M EDC in 0.1 M HEPES buffer at pH 7.5 72 h after the start of the reaction (black line). (C) Polycondensation reaction of nCGp 10 mM in the presence of 0.4 M EDC after 5 min (black), 1 h (red), 2 h (green), 3 h (navy blue), 4 h (blue), 5 h (magenta) and 6 h (dark yellow). (D) Increase of the peak intensity at 250 nm during nCGp polycondensation from figure 8C. Additional reaction details are provided in Materials and Methods.