Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 2000 | public
Journal Article

Mutation detection by electrocatalysis at DNA-modified electrodes

Abstract

Detection of mutations and damaged DNA bases is important for the early diagnosis of genetic disease. Here we describe an electrocatalytic method for the detection of single-base mismatches as well as DNA base lesions in fully hybridized duplexes, based on charge transport through DNA films. Gold electrodes modified with preassembled DNA duplexes are used to monitor the electrocatalytic signal of methylene blue, a redox-active DNA intercalator, coupled to [Fe(CN)_6]^3-. The presence of mismatched or damaged DNA bases substantially diminishes the electrocatalytic signal. Because this assay is not a measure of differential hybridization, all single-base mismatches, including thermodynamically stable GT and GA mismatches, can be detected without stringent hybridization conditions. Furthermore, many common DNA lesions and "hot spot" mutations in the human p53 genome can be distinguished from perfect duplexes. Finally, we have demonstrated the application of this technology in a chip-based format. This system provides a sensitive method for probing the integrity of DNA sequences and a completely new approach to single-base mismatch detection.

Additional Information

© 2000 Nature Publishing Group. Received 14 June 2000; accepted 25 July 2000. We are grateful to the NIH for financial support (GM61077). We also thank M.J. Fitzsimmons and J.L. Lamb in Device Research at JPL for assistance in the fabrication of the DNA chips.

Additional details

Created:
August 21, 2023
Modified:
October 23, 2023