Click chemistry to construct fluorescent oligonucleotides for DNA sequencing

Click chemistry 1,3-dipolar cycloaddition between alkynyl 6-carboxyfluorescein (FAM) and azido-labeled single-stranded (ss) DNA was carried out under aqueous conditions to produce FAM-labeled ssDNA in quantitative yield. The FAM-labeled ssDNA was successfully used as a primer to produce DNA sequencing products with singlebase resolution in a capillary electrophoresis DNA sequencer with laser-induced fluorescence detection.