AVS 46th International Symposium
    Biomaterial Interfaces Group Wednesday Sessions
       Session BI-WeP

Paper BI-WeP6
Hybridization of DNA Monolayers on Gold Observed In Situ with Surface Plasmon Resonance

Wednesday, October 27, 1999, 5:30 pm, Room 4C

Session: Poster Session
Presenter: G.B. Saupe, National Institute of Standards and Technology
Authors: G.B. Saupe, National Institute of Standards and Technology
M.J. Tarlov, National Institute of Standards and Technology
Correspondent: Click to Email
The hybridization of end-tethered single-stranded DNA (ssDNA) probes on gold surfaces with ssDNA targets in salt solutions was monitored with surface plasmon resonance (SPR). SPR is a sensitive technique for measurement of angstrom-level changes resulting from surface DNA hybridization reactions. Surfaces derivatized with DNA are of interest for a variety of applications including genetic diagnostics, forensics, and infectious disease detection. In this study we have used a model system of thiol derivatized ssDNA probes self assembled on gold. The surfaces were subsequently treated with mercaptohexanol to passivate regions of unreacted gold and eliminate non-specific binding of the DNA. The effects of target ssDNA length, base pair mismatches, and the locations of the matching sequence within the target were evaluated in high salt conditions (1M NaCl). Probe coverages, hybridization efficiencies, and times needed for hybridization were measured. Recent data for the hybridization of mixed target solutions, where single basepair mismatched targets compete with exact sequence matched targets to hybridize a single probe, will be discussed.