For this reason a smaller, cheaper, and faster system for DNA sequencing is needed. A proposed system to solve this problem is capillary gel electrophoresis on a microchip. One advantage of the microchip is the materials needed to produce it are inexpensive. The small size also reduces the amounts of costly solvent and precious DNA sample needed to perform the sequencing. Laser-based detection systems are large relative to the chip.
Electrochemical detection is more size compatible with the microchip.
The problem with electrochemical detection is there are not electrochemical tags available for DNA sequencing. Discussion will include the methods of connecting an electrochemically active tag to the DNA by coupling a carboxylic acid to an amine-modified oligonucleotide. The separation of both standard oligonucleotides and sequencing primers will also be discussed.