|
DNA sequencing has become a requisite first step in much of biology and medicine. Traditionally, DNA sequencing has used polyacrylamide gel fractionation to resolve a population of chain-terminated fragments. Alternative approaches include sequencing by hybridization or by synthesis. However, these methods require processive adding and reading of bases. Capillary electrophoresis improves sequencing rates and has been adapted to include fluorescent and electrochemical detection systems. This latter method uses ferrocene derivatives with unique sinusoidal voltammetry frequency responses. However, the small differences in redox potential make it difficult to obtain the resolution necessary for high throughput, sensitivity and accuracy. There is a need for an electrochemical sequencing system not limited by these characteristics.
The invention describes methods and compositions for the electrochemical labeling and sequencing of DNA. Detection is based on novel redox-active tags with tunable electrochemical potentials. The electrochemically-active molecules are based on coordination complexes, whose redox properties can be tuned to match an operative potential range suitable for aqueous capillary electrophoresis of oligonucleotides. The complexes are substitutionally inert, chemically stable and can withstand the conditions employed in DNA manipulation, polymerization and amplification. These electrochemical probes can be employed for the preparation of redox-active NTPs with distinct, non-overlapping, redox potentials suitable for electrochemically-based DNA sequencing.
The improvements in this invention may unlock the potential of electrochemical DNA labeling and sequencing. The ability to adapt this technology to modern high throughput formats (capillary electrophoresis or chips) gives it extreme versatility.
Patents pending : 60/281,276, 10/116,726, 10/137,710, 10/ 336225, 60/305,124
Laboratory Link: Yitzhak Tor
Case Numbers: SD2000-168 and SD2001-228
Keywords: chip, capillary electrophoresis, fluorescent, ferrocene, tunable, redox potentials, electron transfer, transition metal, modified triphosphates.
Inquiries To: invent@ucsd.edu
|
