title: Leukocyte counting from a small amount of whole blood using a size-controlled microcavity array.
abstract: Absolute counting of total leukocytes or specific subsets within small amounts of whole blood is difficult due to a lack of techniques that enable separation of all leukocytes from limited amounts of whole blood. In this study, a microfluidic device equipped with a size-controlled microcavity array for highly efficient separation of leukocytes from submicroliters of whole blood was developed. The microcavity array can separate leukocytes from whole blood based on differences in the size and deformability between leukocytes and other blood cells. Leukocytes recovered on aligned microcavities were continuously processed for image-based immunophenotypic analysis. Our device successfully recovered over 90% of leukocytes in 1 µL of whole blood without pretreatment such as density gradient centrifugation or erythrocyte lysis. In addition, the proposed system successfully performed absolute enumeration of human CD4(+) and CD8(+) leukocytes from 1 µL of whole blood, and the obtained data showed good correlation with conventional flow cytometric analysis. Our microfluidic device has great potential as a tool for a point-of-care leukocyte analysis system.
authors.affiliation: Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Hosokawa
authors.forename: Marie
authors.initials: M
authors.lastname: Asami
authors.forename: Seita
authors.initials: S
authors.lastname: Nakamura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yoshino
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tsujimura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takahashi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakasono
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsunaga
mesh_terms: D019411:Clinical Laboratory Techniques / Q000379:methods; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D007958:Leukocyte Count / Q000379:methods*; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D019095:Point-of-Care Systems