title: Nonlinear concentration gradients regulated by the width of channels for observation of half maximal inhibitory concentration (IC50) of transporter proteins.
abstract: This paper describes a simple microfluidic device that can generate nonlinear concentration gradients. We changed the "width" of channels that can drastically shorten the total microfluidic channel length and simplify the microfluidic network design rather than the "length" of channels. The logarithmic concentration gradients generated by the device were in good agreement with those obtained by simulation. Using this device, we evaluated a probable IC50 value of the ABC transporter proteins by the competitive transport assays at five different logarithmic concentrations. This probable IC50 value was in good agreement with an IC50 value (0.92 μM) obtained at the diluted concentrations of seven points.
authors.affiliation: Kanagawa Academy of Science and Technology (KAST), KSP EAST 303, 3-2-1, Sakado, Takatsu-ku, Kawasaki, Kanagawa, Japan. takeuchi@iis.u-tokyo.ac.jp.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Abe
authors.forename: Koki
authors.initials: K
authors.lastname: Kamiya
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Osaki
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Sasaki
authors.forename: Ryuji
authors.initials: R
authors.lastname: Kawano
authors.forename: Norihisa
authors.initials: N
authors.lastname: Miki
authors.forename: Shoji
authors.initials: S
authors.lastname: Takeuchi
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors* / Q000378:metabolism; D001681:Biological Assay / Q000379:methods*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D011802:Quinidine / Q000494:pharmacology*
chemical_list: D018528:ATP-Binding Cassette Transporters; D004791:Enzyme Inhibitors; D011802:Quinidine