title: A microfluidic device with fluorimetric detection for intracellular components analysis.
abstract: An integrated microfluidic system that coupled lysis of two cell lines: L929 fibroblasts and A549 epithelial cells, with fluorescence-based enzyme assay was developed to determine β-glucocerebrosidase activity. The microdevice fabricated in poly(dimethylsiloxane) consists of three main parts: a chemical cell lysis zone based on the sheath flow geometry, a micromeander and an optical fibers detection zone. Unlike many methods described in literature that are designed to analyse intracellular components, the presented system enables to perform enzyme assays just after cell lysis process. It reduces the effect of proteases released in lysis process on determined enzymes. Glucocerebrosidase activity, the diagnostic marker for Gaucher's disease, is the most commonly measured in leukocytes and fibroblasts using 4-methylumbelliferyl-β-D-glucopyranoside as synthetic β-glucoside. The enzyme cleavage releases the fluorescent product, i.e. 4-methylumbelliferone, and its fluorescence is measured as a function of time. The method of enzyme activity determination described in this paper was adapted for flow measurements in the microdevice. The curve of the enzymatic reaction advancement was prepared for three reaction times obtained from application of different flow rates of solutions introduced to the microsystem. Afterwards, determined β-glucocerebrosidase activity was recalculated with regard to 10(5) cells present in samples used for the tests. The obtained results were compared with a cuvette-based measurements. The lysosomal β-glucosidase activities determined in the microsystem were in good correlation with the values determined during macro-scale measurements.
authors.affiliation: Department of Microbioanalytics, Institute of Biotechnology, Warsaw University of Technology, Warsaw, Poland. rkwapiszewski@ch.pw.edu.pl
authors.forename: Radosław
authors.initials: R
authors.lastname: Kwapiszewski
authors.forename: Maciej
authors.initials: M
authors.lastname: Skolimowski
authors.forename: Karina
authors.initials: K
authors.lastname: Ziółkowska
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Jędrych
authors.forename: Michał
authors.initials: M
authors.lastname: Chudy
authors.forename: Artur
authors.initials: A
authors.lastname: Dybko
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Brzózka
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005470:Fluorometry / Q000295:instrumentation*; D005776:Gaucher Disease / Q000473:pathology; D006801:Humans; D042541:Intracellular Space / Q000201:enzymology*; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D015203:Reproducibility of Results; D001617:beta-Glucosidase / Q000032:analysis* / Q000378:metabolism
chemical_list: D001617:beta-Glucosidase