Fabrication of Polymeric Microfluidic Device for On-Chip Isolation of Nucleic Acids

A microfluidic chip-based solid phase extraction method for isolation of nucleic acids is demonstrated. The chip was fabricated in a cyclic polyolefin by hot embossing with a master. The solid phase was made by in-situ UV polymerization of a monolithic column impregnated with silica particles, and separation was achieved due to irreversible binding of the nucleic acids to the silica particles in the monolith. The porous monolithic column was formed within the channels of the device by photoinitiated polymerization of a mixture of methacrylate and dimethacrylate monomers, UV sensitive free radical initiator and porogenic solvent. The channel surface was photografted with a thin interlayer polymer prior to preparation of the monolith in the channel. The grafted layer covalently attached the monolith and prevented the formation of voids between the monolith and the channel surface. The solid-phase prepared by this method allowed for successful extraction and elution of nucleic acids.