title: Impedimetric and optical interrogation of single cells in a microfluidic device for real-time viability and chemical response assessment.
abstract: We report here a non-invasive, reversible method for interrogating single cells in a microfluidic flow-through system. Impedance spectroscopy of cells held at a micron-sized pore under negative pressure is demonstrated and used to determine the presence and viability of the captured cell. The cell capture pore is optimized for electrical response and mechanical interfacing to a cell using a deposited layer of parylene. Changes in the mechanical interface between the cell and the chip due to chemical exposure or environmental changes can also be assessed. Here, we monitored the change in adhesion/spreading of RAW264.7 macrophages in response to the immune stimulant lipopolysaccharide (LPS). This method enables selective, reversible, and quantitative long-term impedance measurements on single cells. The fully sealed electrofluidic assembly is compatible with long-term cell culturing, and could be modified to incorporate single cell lysis and subsequent intracellular separation and analysis.
authors.affiliation: Sandia National Laboratories, PO Box 5800, Albuquerque, MS 87185-1080, United States. cdjame@sandia.gov
authors.forename: Conrad D
authors.initials: CD
authors.lastname: James
authors.forename: Nigel
authors.initials: N
authors.lastname: Reuel
authors.forename: Eunice S
authors.initials: ES
authors.lastname: Lee
authors.forename: Rafael V
authors.initials: RV
authors.lastname: Davalos
authors.forename: Seethambal S
authors.initials: SS
authors.lastname: Mani
authors.forename: Amanda
authors.initials: A
authors.lastname: Carroll-Portillo
authors.forename: Roberto
authors.initials: R
authors.lastname: Rebeil
authors.forename: Anthony
authors.initials: A
authors.lastname: Martino
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Apblett
mesh_terms: D002470:Cell Survival; D002478:Cells, Cultured; D017097:Electric Impedance; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D046210:Microfluidic Analytical Techniques; D055095:Optics and Photonics; D013057:Spectrum Analysis
chemical_list: D008070:Lipopolysaccharides