Magnetic and Electric Manipulation of a Single Cell in Fluid

2004 ◽  
Vol 820 ◽  
Author(s):  
Hakho Lee ◽  
Tom P. Hunt ◽  
Robert M. Westervelt
Keyword(s):  
Yeast Cell ◽  
Single Cell ◽  
Electric Fields ◽  
Magnetic Beads ◽  
Microfluidic Channel ◽  
Yeast Cells ◽  
Length Scales

AbstractMagnetic and electric manipulation of a single cell in a microfluidic channel was demonstrated using a microelectromagnet matrix and a micropost matrix. The microelectromagnet matrix is two perpendicular arrays of straight wires that are separated and topped by insulating layers. The micropost matrix is an array of post-shaped electrodes embedded in an insulting layer. By controlling the current in each wire of the microelectromagnet matrix or the voltage on each electrode of the micropost matrix, versatile magnetic or electric fields were created on micrometer length scales, controlling the motion of individual cells in fluid. Single or multiple yeast cells attached to magnetic beads were trapped and moved by the microelectromagnet matrix; a single yeast cell was directly trapped and moved by the micropost matrix.

scholarly journals Thermal Shock Response of Yeast Cells Characterised by Dielectrophoresis Force Measurement

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5304
Author(s):  
García-Diego Fernando-Juan ◽  
Mario Rubio-Chavarría ◽  
Pedro Beltrán ◽  
Francisco J. Espinós
Keyword(s):  
Cell Membrane ◽  
Yeast Cell ◽  
Electric Fields ◽  
Force Measurement ◽  
Cell Structure ◽  
Biological Properties ◽  
Yeast Cells ◽  
Uniform Electric Field ◽  
Membrane Conductivity ◽  
Conductivity Cell

Dielectrophoresis is an electric force experienced by particles subjected to non-uniform electric fields. Recently, several technologies have been developed focused on the use of dielectrophoretic force (DEP) to manipulate and detect cells. On the other hand, there is no such great development in the field of DEP-based cell discrimination methods. Despite the demand for methods to differentiate biological cell states, most DEP developed methods have been focused on differentiation through geometric parameters. The novelty of the present work relies upon the point that a DEP force cell measurement is used as a discrimination method, capable of detecting heat killed yeast cells from the alive ones. Thermal treatment is used as an example of different biological state of cells. It comes from the fact that biological properties have their reflection in the electric properties of the particle, in this case a yeast cell. To demonstrate such capability of the method, 279 heat-killed cells were measured and compared with alive cells data from the literature. For each cell, six speeds were taken at different points in its trajectory inside a variable non-uniform electric field. The electric parameters in cell wall conductivity, cell membrane conductivity, cell membrane permittivity of the yeast cell from bibliography explains the DEP experimental force measured. Finally, alive and heat-treated cells were distinguished based on that measure. Our results can be explained through the well-known damage of cell structure characteristics of heat-killed cells.

scholarly journals Optimizing Transformation Frequency of Cryptococcus neoformans and Cryptococcus gattii Using Agrobacterium tumefaciens

2021 ◽  
Vol 7 (7) ◽  
pp. 520
Author(s):  
Jianmin Fu ◽  
Nohelli E. Brockman ◽  
Brian L. Wickes
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Yeast Cell ◽  
Transformation Efficiency ◽  
Transformation Frequency ◽  
Yeast Cells ◽  
Agar Concentration ◽  
Genetic Tool ◽  
Number Of Factors ◽  
Cryptococcus Spp ◽  
Transformation Systems

The transformation of Cryptococcus spp. by Agrobacterium tumefaciens has proven to be a useful genetic tool. A number of factors affect transformation frequency. These factors include acetosyringone concentration, bacterial cell to yeast cell ratio, cell wall damage, and agar concentration. Agar concentration was found to have a significant effect on the transformant number as transformants increased with agar concentration across all four serotypes. When infection time points were tested, higher agar concentrations were found to result in an earlier transfer of the Ti-plasmid to the yeast cell, with the earliest transformant appearing two h after A. tumefaciens contact with yeast cells. These results demonstrate that A. tumefaciens transformation efficiency can be affected by a variety of factors and continued investigation of these factors can lead to improvements in specific A. tumefaciens/fungus transformation systems.

scholarly journals Single-cell analysis for drug development using convex lens-induced confinement imaging

BioTechniques ◽  
2019 ◽  
Vol 67 (5) ◽  
pp. 210-217 ◽  
Author(s):  
Ndeye Khady Thiombane ◽  
Nicolas Coutin ◽  
Daniel Berard ◽  
Radin Tahvildari ◽  
Sabrina Leslie ◽  
...  
Keyword(s):  
Single Cell ◽  
Drug Response ◽  
Drug Exposure ◽  
Cellular Proliferation ◽  
New Technologies ◽  
Detection Sensitivity ◽  
Yeast Cells ◽  
Sample Population ◽  
Phenotypic Analysis ◽  
Convex Lens

New technologies have powered rapid advances in cellular imaging, genomics and phenotypic analysis in life sciences. However, most of these methods operate at sample population levels and provide statistical averages of aggregated data that fail to capture single-cell heterogeneity, complicating drug discovery and development. Here we demonstrate a new single-cell approach based on convex lens-induced confinement (CLiC) microscopy. We validated CLiC on yeast cells, demonstrating subcellular localization with an enhanced signal-to-noise and fluorescent signal detection sensitivity compared with traditional imaging. In the live-cell CLiC assay, cellular proliferation times were consistent with flask culture. Using methotrexate, we provide drug response data showing a fivefold cell size increase following drug exposure. Taken together, CLiC enables high-quality imaging of single-cell drug response and proliferation for extended observation periods.

Magnetophoresis ‘meets’ viscoelasticity: deterministic separation of magnetic particles in a modular microfluidic device

Lab on a Chip ◽  
2015 ◽  
Vol 15 (8) ◽  
pp. 1912-1922 ◽  
Author(s):  
Francesco Del Giudice ◽  
Hojjat Madadi ◽  
Massimiliano M. Villone ◽  
Gaetano D'Avino ◽  
Angela M. Cusano ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Magnetic Particles ◽  
Magnetic Beads ◽  
Microfluidic Channel

Deflection of magnetic beads in a microfluidic channel can be improved through viscoelastic focusing.

THEORETICAL ANALYSIS AND EXPERIMENT OF A NOVEL DEP CHIP WITH 3-D SILICON ELECTRODES

2005 ◽  
Vol 15 (02) ◽  
pp. 231-236 ◽  
Author(s):  
LIMING YU ◽  
FRANCIS E. H. TAY ◽  
GUOLIN XU ◽  
CIPRIAN ILIESCU ◽  
MARIOARA AVRAM
Keyword(s):  
Theoretical Analysis ◽  
Applied Voltage ◽  
Microfluidic Channel ◽  
The Other ◽  
Yeast Cells ◽  
Applied Potential ◽  
Dielectrophoretic Force ◽  
Joule Effect ◽  
Doped Silicon ◽  
Planar Electrodes

This paper presents a novel dielectrophoresis (DEP) device where the DEP electrodes define the channel walls. This is achieved by fabricating microfluidic channel walls from highly doped silicon so that they can also function as DEP electrodes. Compared with planar electrodes, this device increases the exhibited dielectrophoretic force on the particle, therefore decreases the applied potential and reduces the heating of the solution. A DEP device with triangle electrodes has been designed and fabricated. Compared with the other two configurations, semi-circular and square, triangle electrode presents an increased force, which can decrease the applied voltage and reduce the Joule effect. Yeast cells have been used to for testing the performance of the device.

Manipulation of yeast cells in a microfluidic channel using the GPC-based optical trapping system

2006 ◽  
Author(s):  
Ivan R. Perch-Nielsen ◽  
Peter John Rodrigo ◽  
Jesper Glückstad
Keyword(s):  
Optical Trapping ◽  
Microfluidic Channel ◽  
Yeast Cells

scholarly journals Extensive Regulation of Metabolism and Growth during the Cell Division Cycle

2014 ◽  
Author(s):  
Nikolai Slavov ◽  
David Botstein ◽  
Amy Caudy
Keyword(s):  
Gene Expression ◽  
Oxygen Consumption ◽  
Cell Division ◽  
Single Cell ◽  
Single Cells ◽  
Emergent Behavior ◽  
Yeast Cells ◽  
Physiological Data ◽  
Synchronized Cultures ◽  
Metabolic Cycle

Yeast cells grown in culture can spontaneously synchronize their respiration, metabolism, gene expression and cell division. Such metabolic oscillations in synchronized cultures reflect single-cell oscillations, but the relationship between the oscillations in single cells and synchronized cultures is poorly understood. To understand this relationship and the coordination between metabolism and cell division, we collected and analyzed DNA-content, gene-expression and physiological data, at hundreds of time-points, from cultures metabolically-synchronized at different growth rates, carbon sources and biomass densities. The data enabled us to extend and generalize our mechanistic model, based on ensemble average over phases (EAP), connecting the population-average gene-expression of asynchronous cultures to the gene-expression dynamics in the single-cells comprising the cultures. The extended model explains the carbon-source specific growth-rate responses of hundreds of genes. Our physiological data demonstrate that the frequency of metabolic cycling in synchronized cultures increases with the biomass density, suggesting that this cycling is an emergent behavior, resulting from the entraining of the single-cell metabolic cycle by a quorum-sensing mechanism, and thus underscoring the difference between metabolic cycling in single cells and in synchronized cultures. Measurements of constant levels of residual glucose across metabolically synchronized cultures indicate that storage carbohydrates are required to fuel not only the G1/S transition of the division cycle but also the metabolic cycle. Despite the large variation in profiled conditions and in the scale of their dynamics, most genes preserve invariant dynamics of coordination with each other and with the rate of oxygen consumption. Similarly, the G1/S transition always occurs at the beginning, middle or end of the high oxygen consumption phases, analogous to observations in human and drosophila cells. These results highlight evolutionary conserved coordination among metabolism, cell growth and division.

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