title: Colorimetric microchip assay using our own whole blood collected by a painless needle for home medical care.
abstract: We have developed a colorimetric measurement chip that measures triglycerides, total cholesterol, and high-density lipoprotein in 6 μL of whole blood collected with a painless needle. The chip can be used by patients to self-monitor certain health conditions at home. This chip contains a sharp 150 μm diameter stainless steel (SUS) needle that collects blood painlessly. The chip consists of three layers of injection-molded poly(methyl methacrylate) bonded together with two double-sided tapes. Two commercial reagents are used, and the volume ratio of plasma to reagent is doubled from the reagent specification to reduce the optical absorption length (and chip mass) by half. Centrifugal force separates the plasma from the blood, and then weighs out and mixes the plasma and reagents. A zigzag channel allows mixing of the plasma with the reagents mainly by vortex motion due to the centrifugal force generated at the corners of the channel. The measured values correlated well with conventionally tested values.
authors.affiliation: Department of Materials Engineering, Department of Bioengineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. takai@mpc.t.u-tokyo.ac.jp.
authors.forename: Madoka
authors.initials: M
authors.lastname: Takai
authors.forename: Masao
authors.initials: M
authors.lastname: Nagai
authors.forename: Yuji
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Sasao
authors.forename: Akio
authors.initials: A
authors.lastname: Oki
authors.forename: Jun
authors.initials: J
authors.lastname: Nakanishi
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Inokuchi
authors.forename: Chia-Hsien
authors.initials: CH
authors.lastname: Chang
authors.forename: Jun
authors.initials: J
authors.lastname: Kikuchi
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ogawa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Horiike
mesh_terms: D003124:Colorimetry / Q000592:standards; D006699:Home Care Services / Q000592:standards*; D006801:Humans; D056656:Lab-On-A-Chip Devices / Q000592:standards*; D009339:Needles / Q000592:standards*; D010146:Pain / Q000517:prevention & control; D018962:Phlebotomy / Q000295:instrumentation* / Q000592:standards*