AVS 47th International Symposium
    Biomaterial Interfaces Friday Sessions
       Session BI-FrM

Paper BI-FrM5
DNA Probe Structure and Target Length Effects on Hybridization Kinetics and Efficiency of DNA Self-assembled Monolayers

Friday, October 6, 2000, 9:40 am, Room 202

Session: Biomolecular Recognition at Surfaces
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
Optimizing the parameters involved in monolayer DNA hybridization events is important to the emerging DNA sensor array technologies used for a variety of applications including genetic diagnostics, forensics, and infectious disease detection. The objective of our research is to determine how DNA surface coverage, molecular orientation, and sequence identity impact the functionality of DNA array devices. To study these factors we use a model system with short sequences of single-stranded DNA probes self-assembled on gold surfaces through a thiol linker. The gold is also passivated with mercaptohexanol to eliminate non-specific adsorption of DNA to the gold and to enhance the activity of immobilized probes. Surface Plasmon Resonance is used to monitor and derive, in situ, the nanometer-scale thickness changes associated with surface hybridization reactions. Complementary single-stranded DNA targets in high salt buffered solutions hybridize with relatively high efficiency (25-100%) to these surface bound probes. We will report how variations in probe surface structure, the length of ssDNA targets, and the relative position of the complementary sequence in the ssDNA targets affect hybridization kinetics, efficiencies and completion times.