Fig. 2. (A) Reaction scheme for labelling precursor oligonucleotides with dye-NHS ester in solution. (B–D) Representative RP-HPLC-UV/VIS-analyses of (B) crude product (neu-Ser(NH2)-a, DMTr-on) obtained after automated DNA synthesis (analytical HPLC, 15–40% B in 12 min), (C) FIT probe (neu-QB-a) obtained after DMTr removal and post-synthetic labelling with QB-NHS ester (semi-preparative HPLC, 5–30% B in 12 min) and (D) purified FIT probe (neu-QB-a, analytical HPLC, 5–35% B in 12 min). Black lines: 260 nm, red lines: 590 nm; A = 0.1 M triethylammonium acetate, pH 7.5, B = MeCN.
