title: Detection of single enzymatic events in rare or single cells using microfluidics.
abstract: In the present study we demonstrate highly sensitive detection of rare, aberrant cells in a population of wild-type human cells by combining a rolling-circle-enhanced enzyme activity single-molecule detection assay with a custom-designed microfluidic device. Besides reliable detection of low concentrations of aberrant cells, the integrated system allowed multiplexed detection of individual enzymatic events at the single cell level. The single cell sensitivity of the presented setup relies on the combination of single-molecule rolling-circle-enhanced enzyme activity detection with the fast reaction kinetics provided by a picoliter droplet reaction volume and subsequent concentration of signals in a customized drop-trap device. This setup allows the fast reliable analyses of enzyme activities in a vast number of single cells, thereby offering a valuable tool for basic research as well as theranostics.
authors.affiliation: Department of Molecular Biology and Genetics and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Denmark.
authors.forename: Sissel
authors.initials: S
authors.lastname: Juul
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Ho
authors.forename: Jørn
authors.initials: J
authors.lastname: Koch
authors.forename: Felicie F
authors.initials: FF
authors.lastname: Andersen
authors.forename: Magnus
authors.initials: M
authors.lastname: Stougaard
authors.forename: Kam W
authors.initials: KW
authors.lastname: Leong
authors.forename: Birgitta R
authors.initials: BR
authors.lastname: Knudsen
mesh_terms: D015374:Biosensing Techniques; D057075:Enzyme Assays / Q000295:instrumentation*; D005456:Fluorescent Dyes / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007700:Kinetics; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D009841:Oligonucleotides / Q000378:metabolism; D059010:Single-Cell Analysis / Q000295:instrumentation*
chemical_list: D005456:Fluorescent Dyes; D009841:Oligonucleotides