title: Stationary nanoliter droplet array with a substrate of choice for single adherent/nonadherent cell incubation and analysis.
abstract: Microfluidic water-in-oil droplets that serve as separate, chemically isolated compartments can be applied for single-cell analysis; however, to investigate encapsulated cells effectively over prolonged time periods, an array of droplets must remain stationary on a versatile substrate for optimal cell compatibility. We present here a platform of unique geometry and substrate versatility that generates a stationary nanodroplet array by using wells branching off a main microfluidic channel. These droplets are confined by multiple sides of a nanowell and are in direct contact with a biocompatible substrate of choice. The device is operated by a unique and reversed loading procedure that eliminates the need for fine pressure control or external tubing. Fluorocarbon oil isolates the droplets and provides soluble oxygen for the cells. By using this approach, the metabolic activity of single adherent cells was monitored continuously over time, and the concentration of viable pathogens in blood-derived samples was determined directly by measuring the number of colony-formed droplets. The method is simple to operate, requires a few microliters of reagent volume, is portable, is reusable, and allows for cell retrieval. This technology may be particularly useful for multiplexed assays for which prolonged and simultaneous visual inspection of many isolated single adherent or nonadherent cells is required.
authors: Department of Biomedical Engineering andRussell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel;
authors: Jonathan
authors: J
authors: Shemesh
authors: Department of Biomedical Engineering andRussell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel;
authors: Tom
authors: T
authors: Ben Arye
authors: Department of Biomedical Engineering and.
authors: Jonathan
authors: J
authors: Avesar
authors: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115;Harvard School of Engineering and Applied Sciences, Cambridge, MA 02139; and.
authors: Joo H
authors: JH
authors: Kang
authors: Department of Biomedical Engineering and.
authors: Amir
authors: A
authors: Fine
authors: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115;
authors: Michael
authors: M
authors: Super
authors: Department of Biomedical Engineering andRussell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel;
authors: Amit
authors: A
authors: Meller
authors: Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115;Harvard School of Engineering and Applied Sciences, Cambridge, MA 02139; andVascular Biology Program, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115.
authors: Donald E
authors: DE
authors: Ingber
authors: Department of Biomedical Engineering andRussell Berrie Nanotechnology Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel; shulamit@bm.technion.ac.il.
authors: Shulamit
authors: S
authors: Levenberg
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D015169:Colony Count, Microbial; D005347:Fibroblasts / Q000166:cytology*; D006801:Humans; D007938:Leukemia / Q000473:pathology; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D059010:Single-Cell Analysis / Q000295:instrumentation / Q000379:methods*; D013211:Staphylococcus aureus / Q000166:cytology / Q000254:growth & development
keywords: diagnostics; nanoliter array; single cell