title: Temperature alternation by an on-chip microheater to reveal enzymatic activity of beta-galactosidase at high temperatures.
abstract: A method to measure enzymatic activity at high temperatures by rapid temperature alternation of a microreactor with a microheater is proposed. On-chip microreactor and microheater were integrated on a glass plate by MEMS technology; this microheater can control the temperature of the microreactor with a response speed of 34.2 and 31.5 K/s for temperature rise and fall, respectively, with an accuracy of 3 degrees C. The enzyme, beta-galactosidase, was revealed to survive short exposure (4-s pulses) to temperatures above that which would "normally" denature them. Its activity at 60 degrees C was revealed to be approximately 4 times greater than that at room temperature. This method not only gives new kinetic information in biochemistry but also enables application in highly sensitive biosensors.
authors.affiliation: Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo 153-8505, Japan. hideyuki@fujita3.iis.u-tokyo.ac.jp
authors.forename: Hideyuki F
authors.initials: HF
authors.lastname: Arata
authors.forename: Yannick
authors.initials: Y
authors.lastname: Rondelez
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Noji
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fujita
mesh_terms: D006358:Hot Temperature; D056656:Lab-On-A-Chip Devices; D046208:Microchip Analytical Procedures / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D001616:beta-Galactosidase / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D001616:beta-Galactosidase