In situ surface plasmon resonance imaging detection of DNA hybridization to oligonucleotide arrays on gold surfaces

A new method for constructing oligonucleotide arrays on gold surfaces has been developed, and these arrays have been used in DNA hybridization experiments with in situ surface plasmon resonance (SPR) imaging detection. The detection technique was able to differentiate between single-and double-stranded DNA regions on the gold surface. The hybridization of both oligonucleotides and PCR-amplified DNA fragments was detectable, with the latter exhibiting slower hybridization kinetics. Temperature control of the in situ SPR cell was used to discriminate between perfectly matched duplexes and single-base-mismatched duplexes. The SPR detection technique requires no label on the DNA, but fluorescently labeled targets were also tested and detected by fluorescence imaging as an independent verification of the hybridization behavior of these DNA arrays, The in situ SPR imaging method for detection of DNA hybridization is expected to complement other existing methods for study of DNA interactions and might find future uses in mutation screening assays and DNA resequencing.