Abstract: It is an object to provide a small-hole electrical discharge machining device to discharge the machining debris efficiently and to drill a small hole by electrical discharge machining at a high speed.

Abstract: The present invention provides a light-emitting control knob capable of consistently maintaining a beautiful design without a problem, such as discoloration or rubbing-off, despite use of a long period because a light-blocking metal plate having light-emitting display windows formed therein is stacked and formed on a top surface of a knob body and of providing a much more beautiful and high-class design than a conventional control knob because surface processing unique to metal can be performed on the light-blocking metal plate. The light-emitting control knob in accordance with the present invention includes a knob body made of transparent or semitransparent synthetic resins which transmit light and a light-blocking metal plate formed of a metal plate stacked on a top surface of the knob body and configured to have light-emitting display windows formed therein.

Abstract: It is an object to provide a small-hole electrical discharge machining device to discharge the machining debris efficiently and to drill a small hole by electrical discharge machining at a high speed.

Abstract: A device for the purification of synthetic oligonucleotides, characterized by comprising means for switching between purification with an affinity column which recognizes trityl groups, in cases where trityl groups are bonded, and purification with a disposable stepwise reverse phase chromatography column in cases where no trityl groups are bonded. The device makes it possible for any person to easily perform high-degree purification, simply by setting the synthesized oligonucleotides. Furthermore, it accomplishes both a method using an affinity column cartridge and a method for purification by HPLC.