A new solid-phase chemical DNA sequencing method which uses streptavidin-coated magnetic beads

To simplify the chemical DNA sequencing protocol, we developed a new solid-phase method which uses streptavidin-coated magnetic beads. This method is based on the finding that the biotinylated DNA-streptavidin complex was stable under the conditions for some chemical sequencing reactions. The 5'-biotinylated DNA generated by the polymerase chain reaction was first captured by streptavidin-coated magnetic beads and then subjected to a set of simplified chemical sequencing reactions on the beads at room temperature. Followed by the piperidine cleavage reaction, the products were resolved by gel electrophoresis, transferred onto a nylon membrane and visualized by chemiluminescent detection. As a consequence, high-quality sequencing ladders were obtained, due to complete removal of contaminating chemicals, without the time-consuming precipitation/centrifugation steps used in the conventional chemical sequencing protocol.