A micro-fabricated capillary electrophoresis chip for DNA pre-concentration and separation

A simple online DNA pre-concentration and separation method by using a micro capillary electrophoresis (CE) chip integrated with a normally-closed valve activated by pneumatic suction has been developed. The normally-closed valve with anionic surface charges forms a nanoscale channel only allows the passage of electric current but traps the DNA samples so that they can be pre-concentrated. Obvious fluorescent-labeled DNA concentration is observed at the pre-concentration area. The fX174 DNA/HaeIII markers separation signals are significantly enhanced comparing with the results of a traditional cross-shaped micro CE chip. Therefore, successful DNA pre-concentration for signal enhancement and separation analysis can be performed by using this new micro CE chip.