title: Real-time detection and quantification of DNA hybridization by an optical biosensor.
abstract: The use of an optical biosensor, the resonant mirror, for direct and rapid detection of DNA-DNA hybridization has been demonstrated. Biotinylated oligonucleotide probes were immobilized on the sensor surface, via streptavidin, and the hybridization of a complementary target oligonucleotide (40-mer) was monitored in real time. The interaction at the sensor surface was shown to be sequence specific under conditions of low stringency. Regeneration of the surface-immobilized probe was possible, allowing reuse without a significant loss of hybridization activity. A comparison of probes indicated that the relative position of complementary sequence and the length of probe affected the hybridization response obtained. The potential of the sensor for quantitation of a hybridized DNA target was investigated. From radiolabeling data, the lowest amount of hybridized target sequence which could be determined directly was 19.9 fmol/mm2 (263 pg/mm2) of sensor surface. The dependence of the sensor response on the concentration of probe and target oligonucleotide was established. Utilizing the assay as an end-point determination method, the lowest detectable concentration of target oligonucleotide (40-mer) was 9.2 nM. This compares favorably to other sensor methods described previously without the requirement for labels.
authors.affiliation: Laboratory of the Government Chemist, Teddington, Middlesex, U.K.
authors.forename: H J
authors.initials: HJ
authors.lastname: Watts
authors.forename: D
authors.initials: D
authors.lastname: Yeung
authors.forename: H
authors.initials: H
authors.lastname: Parkes
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques; D004247:DNA / Q000032:analysis*; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization
chemical_list: D004247:DNA