Oligonucleotide hybridization observed by surface plasmon optical techniques

Surface plasmon spectroscopy and microscopy are employed to study the hybridization reaction of an oligonucleotide ten-mer from solution to its complement immobilized to a solid support. It is shown that a dilute target monolayer is necessary to allow for an effective dimerization process. Parallel multi-site detection of the DNA binding is demonstrated to be possible with surface plasmon microscopy without the need for any extra labeling of the reaction partners. The simultaneous quantitative evaluation of the degree of dimerization to many different target areas, each as small as a few μm2 and each functionalized by different oligonucleotide sequences, can be accomplished by two-dimensional image analysis and should be relevant for DNA sequencing protocols.