AVS 52nd International Symposium
    DNA Topical Conference Monday Sessions
       Session DN+BI-MoA

Invited Paper DN+BI-MoA3
Surface Enzyme Reactions for Enhancing SPR Imaging Measurements of DNA Microarrays

Monday, October 31, 2005, 2:40 pm, Room 311

Session: DNA Detection and Sensing
Presenter: R.M. Corn, University of California, Irvine
Correspondent: Click to Email

The identification and application of bioaffinity interactions in a large scale array format has become an indispensable tool for modern biological research. Bioaffinity interactions such as DNA-DNA and DNA-protein interactions are now employed in an array format to quickly ascertain the presence of a particular DNA or RNA sequence in a sample, to detect and identify microbial and viral species, and to verify efficacy and function in medical diagnostics. In addition to the detection of DNA, microarrays are can be for the identification of new DNA-protein bioaffinity interactions such as and protein-protein binding. The surface-sensitive optical technique of surface plasmon resonance (SPR) imaging is a powerful "label free" measurement that can be used in an array format for the detection of bioaffinity interactions. SPR imaging detects the presence of a biopolymer on a chemically modified gold surface by the change in the local index of refraction that occurs upon adsorption. This talk will highlight the use of surface DNA enzyme reactions in conjunction with SPR imaging measurements to either provide enhanced biochemical selectivity or to amplify the optical response of the bioaffinity adsorption events. For example, we have recently used the enzyme RNase H to detect DNA adsorption onto RNA microarrays from femtomolar solutions. Further experiments on the reaction of Exo III with double-stranded DNA arrays and the use of Exo I with single-stranded DNA arrays will be employed to detail the kinetics of the surface enzyme reactions, which can be described with a combination of Langmuir and Michaelis-Menten concepts.