A PCR reactor with an integrated alumina membrane for nucleic acid isolation

Recently, there has been a growing interest in point-of-care devices capable of detecting nucleic acids (NA) in clinical and environmental samples. Nucleic acid detection requires, however, various sample preparation steps that complicate device operation. An attractive remedy is to integrate many, if not all, sample preparation operations and nucleic acid amplification into a single reaction chamber. A microfluidic chip that integrates, in a single chamber, polymerase chain reaction (PCR) amplification with solid-phase extraction of nucleic acids using a nanoporous, aluminium oxide membrane (AOM) is described. Samples suspected of containing target bacteria and/or viruses are mixed with lysis agents and a chaotropic salt and loaded into a plastic chip housing a nanoporous, aluminium oxide membrane. The nucleic acids in the lysate bind to the membrane. The membrane is then washed, the chamber is filled with the PCR reaction reagents, and the chamber's temperature is cycled to amplify the captured nucleic acids and produce detectable products. Both DNA and RNA (with reverse-transcription) isolation and amplification are demonstrated. Due to the dry membrane's high resistance to liquid flow, a specialized flow control system was devised to facilitate sample introduction and membrane washing.