Automated system for purification of dye-terminator sequencing products eliminates up-stream purification of templates

The quality of sequencing results is to a large extent determined by the purity of the template and the purification of the sequencing products. Fragments that can act as unspecific primers and templates are removed before gel analysis, and the background of unspecific signals is highly reduced. Purification of the sequencing products is needed to remove salts, nucleotides, proteins and template DNA that can interfere with the gel separation. We have developed a product, DYNAPURE(TM) Dye Terminator Removal, that specifically isolates and purifies the sequencing products in 10 min. The method is based on biotinylated sequencing primers and superparamagnetic streptavidin beads. A PCR product is sequenced using a biotinylated sequencing primer; and the sequencing products are then bound to streptavidin beads in a 5-min reaction. The bead-DNA complexes are magnetically separated from the rest of the solution, and the remaining buffer constituents are washed away with TE buffer or with 70% ethanol. The whole procedure can be automated on liquid-handling robots fitted with a magnet station. The method eliminates purification of templates before cycle sequencing.