RESUMO
PCR amplification, DNA hybridization, and a hybridization wash have been integrated in a disposable monolithic DNA device, containing all of the necessary fluidic channels and reservoirs. These integrated devices were fabricated in polycarbonate plastic material by CO2 laser machining and were assembled using a combination of thermal bonding and adhesive tape bonding. Pluronics polymer phase change valves were implemented in the devices to fulfill the valving requirements. Pluronics polymer material is PCR compatible, and 30% Pluronics polymer valves provide enough holding pressure to ensure a successful PCR amplification. By reducing the temperature locally, to approximately 5 degrees C, Pluronics valves were liquefied and easily opened. A hybridization channel was made functional by oligonucleotide deposition, using Motorola proprietary surface attachment chemistry. Reagent transport on the device was provided by syringe pumps, which were docked onto the device. Peltier thermal electrical devices powered the heating and cooling functionality of the device. Asymmetrical PCR amplification and subsequent hybridization detection of both Escherichia coli K-12 MG1655 and Enterococcus faecalis DNAE genes have been successfully demonstrated in these disposable monolithic devices.