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 hybridizati on experiments with in situ surface plasmon resonance (SPR) imaging de tection. The detection technique was able to differentiate between sin gle-and double-stranded DNA regions on the gold surface. The hybridiza tion of both oligonucleotides and PCR-amplified DNA fragments was dete ctable, with the latter exhibiting slower hybridization kinetics. Temp erature control of the in situ SPR cell was used to discriminate betwe en perfectly matched duplexes and single-base-mismatched duplexes. The SPR detection technique requires no label on the DNA, but fluorescent ly labeled targets were also tested and detected by fluorescence imagi ng as an independent verification of the hybridization behavior of the se DNA arrays, The in situ SPR imaging method for detection of DNA hyb ridization is expected to complement other existing methods for study of DNA interactions and might find future uses in mutation screening a ssays and DNA resequencing.