Microchip module for blood sample preparation and nucleic acid amplification reactions

A computer numerical control-machined plexiglas-based microchip module was designed and constructed for the integration of blood sample preparation an d nucleic acid amplification reactions. The microchip module is comprised o f a custom-made heater-cooler for thermal cycling, a series of 254 mum x 25 4 mum microchannels for transporting human whole blood and reagents in and out of an 8-9 muL dual-purpose (cell isolation and PCR) glass-silicon micro chip. White blood cells were first isolated from a small volume of human wh ole blood (<3 <mu>L) in an integrated cell isolation-PCR microchip containi ng a series of 3.5-mum feature-sized "weir-type" filters, formed by an etch ed silicon dam spanning the flow chamber. A genomic target, a region in the human coagulation Factor V gene (226-bp), was subsequently directly amplif ied by microchip-based PCR on DNA released from white blood cells isolated on the filter section of the microchip mounted onto the microchip module. T he microchip module provides a convenient means to simplify nucleic acid an alyses by integrating two key steps in genetic testing procedures, cell iso lation and PCR and promises to be adaptable for additional types of integra ted assays.