We report on genotyping of single nucleotide polymorphisms (SNP) by melting curve analysis (MCA) on DNA microarrays in a plastic microfluidic system with integrated heaters using lamination foils. Thin-film micro-heaters were processed on polyethylene napthalate (PEN) foil in only one metallization step. DNA microarrays were prepared directly on the PEN surface without the need of surface pre-treatment via UV-mediated immobilization of the spotted DNA microarrays. MCA in microfluidic channels is demonstrated at a ramping rate of 60°C/min, enabling ultra-rapid (50 seconds) SNP analysis.