Nobuyoshi Tajima

Free-flow electrophoresis in a microfabricated chamber with a micromodule fraction separator. Continuous separation of proteins.

Continuous free flow electrophoresis of proteins was carried out in a microfabricated free flow electrophoresis (mFFE) module with the 30-microm thick slit of the separation. The newly developed micromodule fraction separator (MFS) was attached to the down-stream end site of the separation chamber of mFFE. By using the MFS, electrolyte solution from the separation chamber was introduced to the peristaltic pump without disturbing the electrolyte solution flow at the bottom side of the chamber. The separation of protein mixture samples was achieved by a hydroxypropylmethylcellulose pretreatment coating of the separation chamber. The pretreatment of the sample chamber effectively suppressed electroosmotic flow. All fractionated samples were collected using the MFS after continuous elecrophoresis and analyzed by reversed-phase HPLC. From the results of HPLC analyses none of the cytochrome c fractions at the other ports revealed cross talk phenomena at adjacent ports. A similar result occurred for the myoglobin. This means that these proteins were completely separated from each other by continuous mFFE, and the MFS functioned efficiently during continuous electrophoresis.

Spectral bistability of two-dimensional molecular assemblies due to a peculiar crystal-to-crystal phase transition

An ordered cast film of azobenzene-containing molecular membranes had two stable crystalline states at room temperature; spectral bistability of guest cyanine dye reflecting two crystalline states was observed as well as the azobenzene chromophore.

Effect of thermal treatment on surface monolayer and Langmuir-Blodgett film prepared by polyion complex technique

Abstract A stable monolayer of a polymeric ion complex was formed at the air-water interface when dioctadecyldimethylammonium bromide was spread on an aqueous solution of potassium poly(vinyl sulphate). The polyion-complexed monolayer was annealed by a flat-panel heater located above the surface monolayer. The annealed monolayer deposited on an indium tin oxide electrode as a Y-type Langmuir-Blodgett film effectively blocked the electrochemical oxidation-reduction reaction of the ferricyanide ion.

A New Application by Microfabricated Free Flow Electrophoresis Module

Using anion and cation dyes, separation and interaction between those dyes was investigated with a microfabricated free flow electrophoresis (FFE) module. Crossing the sample stream of dye solution in the separation bed of the FFE, interaction strength of two dyes was evaluated. The results suggested that the FFE module could use as a microreactor.

Continuous Free-Flow Electrophoresis Separation of Proteins by Microfabricated Chamber with Micromodule Fraction Separator

The technology of free flow electrophoresis (FFE) is now more than 40 years old [1] and the field is now experiencing a new development through microfabricated free flow electrophoresis (mFFE) module [2]. This paper will describe one system’s development and application of mFFE technology.

Free Flow Electrophoresis Module for Rapid Sample Preparation

Newly designed FFE modules and a control system were developed. The separation time during the sample flow from the inlet to the outlets was one second when a mixture of genomic DNA, plasmid and albmin was used as a sample. Very high-speed separation and collection system was realized by the microfabricated FFE module.