著者
Atsushi KOBAYASHI Yukari SATO Fumio MIZUTANI
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.65, no.11, pp.2392-2396, 2001 (Released:2002-08-30)
参考文献数
28
被引用文献数
9

The adsorption properties, amount and specific activity of lipase D from Rhizopus delemar were investigated by employing a gold substrate modified with seven kinds of thiol monolayer. Quartz crystal microbalance measurements revealed that the amount of the enzyme adsorbed to the hydrophobic monolayers (e.g. benzenethiol) was much higher than that to the hydrophilic monolayers (e.g. 3-mercaptopropanoic acid). In contrast, lipase D adsorbed to the hydrophilic, 2-amino-1-ethanethiol monolayer showed the highest specific activity, the value being 300-fold higher than for the same enzyme dissolved in an aqueous medium.
著者
Tomoyuki YASUKAWA Asa MORISHIMA Masato SUZUKI Junya YOSHIOKA Keitaro YOSHIMOTO Fumio MIZUTANI
出版者
The Japan Society for Analytical Chemistry
雑誌
Analytical Sciences (ISSN:09106340)
巻号頁・発行日
vol.35, no.8, pp.895-901, 2019-08-10 (Released:2019-08-10)
参考文献数
39
被引用文献数
2 7

We applied a fabrication method for the formation of island organization of cells based on a three-dimensional (3D) device for negative dielectrophoresis (n-DEP) to produce cell aggregates with uniform numbers of cells rapidly and simply. The intersections formed by rotating the interdigitated array (IDA) with two combs of band electrodes on the upper substrate by 90° relative to the IDA with two combs on the lower substrate were prepared in the device. The AC voltage was applied to a comb on the upper substrate and a comb on the lower substrate, while AC voltage with opposite phase was applied to another comb on the upper substrate and another comb on the lower substrate. Cells dispersed randomly were directed toward the intersections with relatively lower electric fields due to n-DEP, which formed by AC voltage applied bands with the identical phase, resulting in the formation of island patterns of cells. The cells accumulated at intersections were promoted to form the cell aggregates due to the close contact together. The production of cell aggregations adhered together was easily found by the dispersion behavior after switching the applied frequency to convert the cellular pattern. When cells were accumulated at the intersections by n-DEP for 45 min, almost accumulations of cells were adhered together, and hence a formations of cell aggregations. By using the present method, we can rapidly and simply fabricate cell aggregations with a uniform number of cells.