DNA analysis, specifically single nucleotide polymorphism (SNP) detection, is becoming increasingly important in rapid
diagnostics and disease detection. Temperature is often controlled to help speed reaction rates and perform melting of
hybridized oligonucleotides. The difference in melting temperatures, Tm, between wild-type and SNP sequences,
respectively, to a given probe oligonucleotide, is indicative of the specificity of the reaction. We have characterized
Tm's in solution and on a solid substrate of three sequences from known mutations associated with Cystic Fibrosis.
Taking advantage of Tm differences, a microheater array device was designed to enable individual temperature control
of up to 18 specific hybridization events. The device was fabricated at Sandia National Laboratories using surface
micromachining techniques. The microheaters have been characterized using an IR camera at Sandia and show
individual temperature control with minimal thermal cross talk. Development of the device as a real-time DNA
detection platform, including surface chemistry and associated microfluidics, is described.
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