Multithermal DNA micro-array chip for rapid DNA melting temperature measurement and advanced SNP discrimination

This paper describes a micromachined device dedicated to measure DNA target-probe melting temperatures and to discriminate multiplex single nucleotide polymorphisms on a standard DNA micro-array slide. The microfluidic system of the chip divided the micro-array slide into eight washing chambers, each providing different thermal conditions for stringent washing. Melting temperature of DNA target-probe hybrids measured by the chip corresponded well to the melting curves determined by standard methods. The long DNA capture probes provided higher melting temperatures then shorter probes, and the perfectly matched hybrids had higher melting temperatures than the corresponding hybrids containing SNP mutation, as expected. Due to the wide washing temperature range provided simultaneously by the chip, it was possible both to create and to find optimal washing temperatures for discrimination of several SNPs in a single experiment.