Microbiochemical reactors for enzymatic reactions including cell-free mRNA translation

As the first step toward the 'lab on a chip' or 'cell on a chip' concept, several microbiochemical reactors were fabricated using conventional MEMS (microelectromechanical systems) techniques: silicon anisotropic etching and glass-silicon anodic bonding. The microreactors have main reaction channels which are 14 mm long, 200-800 μm wide, and 20 μm deep. In these channels, enzymatic reactions - luciferin-luciferase reaction and cell-free mRNA translation - were demonstrated. Luminescence induced by the luciferin-luciferase reaction was observed in two ways, by photograph on a high-speed film and sensitive video imaging. In both cases, diffusion-based mixing in the microreactors was clearly visualized. In the cell-free protein synthesis experiment, the amount of polyphenylalanine, which was synthesized by translating polyuridylic acid template in the microreactors, was determined using radioisotope assay.