ABSTRACT

In this paper we report the use of Surface Second Harmonic to detect DNA hybridisation on glass slides. Spots of 1ul of a single stranded 20 mer oligonucleotide (probes) were baked on Silanased glass slides and subsequently hybridised with the complementary strand. Surface Second Harmonic signal was generated at the slide surface by exposing it to a flashlamp pumped Nd:YAG laser operating at 1064 nm. The SSH signal, at 532nm, of the baked and washed slide was found to increase dramatically at the location corresponding to the probe’s spots. The SSH intensity also varied after the hybridisation step, which suggests that our SSH system can detect DNA hybridisation. Both deposition and hybridisation of the probes were confirmed with fluorescein labelled oligonucleotides. This work demonstrates the successful application of SSHG to hybridisation assay.