Yutaka Unuma

Fully automated two-dimensional electrophoresis system for high-throughput protein analysis.

We developed a fully automated electrophoresis system for rapid and highly reproducible protein analysis. All the two-dimensional (2D) electrophoresis procedures including isoelectric focusing (IEF), on-part protein staining, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and in situ protein detection were automatically completed. The system comprised Peltiert devices, high-voltage generating devices, electrodes, and three disposable polymethylmethacrylate (PMMA) parts for IEF, reaction chambers, and SDS-PAGE. Because of miniaturization of the IEF part, rapid IEF was achieved in 30 min. A gel with a tapered edge gel on the SDS-PAGE part realized a connection between the parts without use of a gluing material. A biaxial conveyer was employed for the part relocation, sample introduction, and washing processes to realize a low-maintenance and cost-effective automation system. Performances of the system and a commercial minigel system were compared in terms of detected number, resolution, and reproducibility of the protein spots. The system achieved high-resolution comparable to the minigel system despite shorter focusing time and smaller part dimensions. The resulting reproducibility was better or comparable to the performance of the minigel system. Complete 2D separation was achieved within 1.5 h. The system is practical, portable, and has automation capabilities.

Document scanner using polymer waveguides with a microlens array

A document scanner using polymer waveguides with a microlens array was developed. The waveguide grooves and the microlenses were fabricated simultaneously by injection molding. The cores of the waveguides were formed by squeegeeing. The waveguides have multiple sharp bends to minify the image and also to reduce the size of the scanner. The microlens had a root-mean-square wavefront aberration of 0.06 λ(λ = 633 nm), and the waveguide had a transmission loss of less than 0.1 dB/cm at 633 nm. The optical system was designed to be telecentric so that the scanner had a depth of field greater than 6.0 mm (at 4 lp/mm).