The effect of locked nucleic acid (LNA) modification on hybridization kinetics of DNA duplex formation has been studied at varying salt concentration (Na(+) and Mg(2+)) using surface-plasmon resonance. The study suggested that the increased stability of LNA containing duplexes mainly originates from the slower dissociation rates constants of the duplexes. An increase in salt concentration increased the binding affinity of the individual duplexes by raising their association rate constants. Monitoring the change in binding affinity with respect to salt concentration revealed that of LNA-associated enhancement in helical stability mainly results from the changes in the non-electrostatic interactions upon duplex formation.