Handling of biological cells using fluid integrated circuit

Washizu, Masao; Nanba, T.; Masuda, S.

doi:10.1109/ias.1988.25294

Cited by 22 publications

(9 citation statements)

References 2 publications

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“…It has been shown (Washizu et al 1990) that in 2D (which is relevant to the micropit as the pit is rotationally symmetric) cells tend to move, due to positive dielectrophoresis, towards the edges of convex objects and become trapped. The locations for trapping a cell were therefore predicted to be as shown in Fig.…”

Section: Electric Field Simulationmentioning

confidence: 97%

A novel micropit device integrates automated cell positioning by dielectrophoresis and nuclear transfer by electrofusion

Clow

Gaynor

Oback

2010

Biomed Microdevices

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Nuclear transfer (NT) cloning involves manual positioning of individual donor-recipient cell couplets for electrofusion. This is time-consuming and introduces operator-dependent variation as a confounding parameter in cloning trials. In order to automate the NT procedure, we developed a micro-fluidic device that integrates automated cell positioning and electrofusion of isolated cell couplets. A simple two layer micro-fluidic device was fabricated. Thin film interdigitated titanium electrodes (300 nm thick, 250 microm wide and 250 microm apart) were deposited on a solid borosilicate glass substrate. They were coated with a film of electrically insulating photosensitive epoxy polymer (SU-8) of either 4 or 22 microm thickness. Circular holes ("micropits") measuring 10, 20, 30, 40 or 80 microm in diameter were fabricated above the electrodes. The device was immersed in hypo-osmolar fusion buffer and manually loaded with somatic donor cells and recipient oocytes. Dielectrophoresis (DEP) was used to attract cells towards the micropit and form couplets on the same side of the insulating film. Fusion pulses between 80 V and 120 V were applied to each couplet and fusion scored under a stereomicroscope. Automated couplet formation between oocytes and somatic cells was achieved using DEP. Bovine oocyte-oocyte, oocyte-follicular cells and oocyte-fibroblast couplets fused with up to 69% (n = 13), 50% (n = 30) and 78% (n = 9) efficiency, respectively. Fusion rates were comparable to parallel plate or film electrodes that are conventionally used for bovine NT. This demonstrates proof-of-principle that a micropit device is capable of both rapid cell positioning and fusion.

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Section: Electric Field Simulationmentioning

confidence: 97%

A novel micropit device integrates automated cell positioning by dielectrophoresis and nuclear transfer by electrofusion

Clow

Gaynor

Oback

2010

Biomed Microdevices

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“…Advances in microfabrication methods for MEMS have achieved micrometer precision for massively parallel fabrication, and have therefore made these micro-fluidic efforts economically feasible. Early efforts include the electrical manipulation of cells and macromolecules by Washizu, Sato and coworkers 12,13 and Fuhr and coworkers 14 . Each group used electrode arrays to generate electric fields to control individual mammalian cells (approximately 30 micrometers in diameter) in a liquid.…”

Section: Introductionmentioning

confidence: 99%

Arrays of micro-electrodes and electromagnets for processing of electro-magneto-elastic multifunctional composite materials

2003

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Large arrays of MEMS with programmable electrodes and electromagnets are used to achieve microscale positioning of particles, whiskers, and fibers in polymer matrix materials. Arrays of MEMS are placed above and beneath thin layers of a random particle-filled liquid polymer. Microscale variations in the electric and magnetic fields are then used to control body forces that move the piezoelectric and piezomagnetic particles. The body forces are due to the gradients in the E and B fields. Such body forces are generally small on a macroscopic scale. However, standard microfabrication methods enable the generation of very high gradients in E and B on the microscale, therefore generating body forces large enough to overcome microscopic sedimentation forces, viscous forces, and the mutual attraction of particles. We discuss the free body diagram of a particle, the design of MEMS arrays using a finite element code (ANSYS) to determine the electric and magnetic fields, and the fabrication of the MEMS arrays. Currently there is no way to affordably arrange the particles in the optimal microscale pattern in composite materials. Ideally, the current method will provide an affordable and versatile method of patterning the microstructure of multi-functional composite materials, sensors, actuators.

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“…Data for every cell (129) and every frequency (75, 100, 150, 400, 800, 1000, 3000 and 5000 kHz) are included in the Fig.4. The continuous line shows the density for the Fl o -parameter, which is a function of the effective polarizability R e [ f c~] and the "squared radius" of the cell as (13). The density for F l oparameter ranges from -80% to 80% and has two density maxima at 10% and -30%.…”

Section: Population Datamentioning

confidence: 99%

“…The effective polarizability Re[f&] is calculated using (13) with data of average F l oparameter. We have taken the relative permittivity for the mannitol as 78 [lo], the geometric parameter of the chamber as l / a = 1.08 and the average squared radius of 40 kHz with a conductivity of 2.2 mS/m is in agreement because the crossover-frequency increases with the conductivity of the medium.…”

Section: Population Datamentioning

confidence: 99%

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Dielectrophoretic force measurements in yeast cells by the Stokes method

Cruz

García-Diego²

IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting

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A chamber and method for the measurement of dielectrophoretic (DEP) force in yeast cells (Saccharomyces cerevisiae) is described. The physical method uses the Stokes drag force and a V-shaped chamber. Velocity measurements were induced over the frequency range of between 50 kHz and 5 MHz for a suspending medium of 2.2 mS/m in conductivity. Average values of DEP force and effective polarizability have been determined from the velocity measurements. Experimental data with single cells confirm the theoretical expression for the axial profile of the electric field. The results show that this method-and-chamber system is an accurate tool for measuring of DEP force over single cells. Population data of 129 cells confirm the theory showing that the DEP velocity distribution density of the population is similar to the cellular "square radius".

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Handling of biological cells using fluid integrated circuit

Cited by 22 publications

References 2 publications

A novel micropit device integrates automated cell positioning by dielectrophoresis and nuclear transfer by electrofusion

A novel micropit device integrates automated cell positioning by dielectrophoresis and nuclear transfer by electrofusion

Arrays of micro-electrodes and electromagnets for processing of electro-magneto-elastic multifunctional composite materials

Dielectrophoretic force measurements in yeast cells by the Stokes method

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