Charge injection through nanocomposite electrode in microfluidic channel for electrical lysis of biological cells

2013 ◽  
Author(s):  
Madhusmita Mishra ◽  
Anil Krishna ◽  
Aman Chandra ◽  
B. M. Shenoy ◽  
G. M. Hegde ◽  
...  
Keyword(s):  
Microfluidic Channel ◽  
Charge Injection ◽  
Biological Cells ◽  
Electrical Lysis

Mechanism of Cell Lysis in Microfluidic Channel With Integrated Nanocomposite Electrodes

2013 ◽  
Author(s):  
Madhusmita Mishra ◽  
Anil Krishna Koduri ◽  
Aman Chandra ◽  
D. Roy Mahapatra ◽  
G. M. Hegde
Keyword(s):  
Electric Field ◽  
Microfluidic Channel ◽  
Cell Lysis ◽  
Bacterial Cells ◽  
Nano Composite ◽  
Time Resolved ◽  
Ac Electric Field ◽  
Cell Dispersion ◽  
Electrical Lysis ◽  
Nanocomposite Electrodes

This paper reports on the characterization of an integrated micro-fluidic platform for controlled electrical lysis of biological cells and subsequent extraction of intracellular biomolecules. The proposed methodology is capable of high throughput electrical cell lysis facilitated by nano-composite coated electrodes. The nano-composites are synthesized using Carbon Nanotube and ZnO nanorod dispersion in polymer. Bacterial cells are used to demonstrate the lysis performance of these nanocomposite electrodes. Investigation of electrical lysis in the microchannel is carried out under different parameters, one with continuous DC application and the other under DC biased AC electric field. Lysis in DC field is dependent on optimal field strength and governed by the cell type. By introducing the AC electrical field, the electrokinetics is controlled to prevent cell clogging in the micro-channel and ensure uniform cell dispersion and lysis. Lysis mechanism is analyzed with time-resolved fluorescence imaging which reveal the time scale of electrical lysis and explain the dynamic behavior of GFP-expressing E. coli cells under the electric field induced by nanocomposite electrodes. The DNA and protein samples extracted after lysis are compared with those obtained from a conventional chemical lysis method by using a UV–Visible spectroscopy and fluorimetry. The paper also focuses on the mechanistic understanding of the nano-composite coating material and the film thickness on the leakage charge densities which lead to differential lysis efficiency.

FABRICATION AND TESTING OF POLYDIMETHYLSILOXANE (PDMS) MICROCHANNEL FOR LAB-ON-CHIP (LOC) MAGNETICALLY-LABELLED BIOLOGICAL CELLS SEPARATION

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Ummikalsom Abidin ◽  
Jumril Yunas ◽  
Burhanuddin Yeop Majlis
Keyword(s):  
Microfluidic Channel ◽  
Biological Cells ◽  
Negative Photoresist ◽  
Magnetic Separator ◽  
Lab On Chip ◽  
Fluid Handling ◽  
Pdms Microchannel ◽  
On Chip ◽  
A Current ◽  
Microfluidics Channel

Microfluidics channel of micron- to millimeter in dimension has been widely used for fluid handling in transporting, mixing and separating biological cells in Lab-on-Chip (LoC) applications. In this research, fabrication and testing of Polydimethylsiloxane (PDMS) microfluidic channel for Lab-on-chip magnetically-labelled biological cells separation is presented. The microchannel is designed with one inlet and outlet. A reservoir or chamber is proposed as an extra component of the microchannel design for ease of trapping the intended biological cells in LoC magnetic separator system. The PDMS microchannel of circular-shaped chamber geometry has been successfully fabricated using replica molding technique from SU-8 negative photoresist mold. An agglomerate-free microbeads flowing has been observed using the fabricated PDMS microchannel. Trapping of microbeads in the trapping chamber with 2.0 A current supply in the continuous microfluidics flow > 100 mL/min has also been demonstrated. In conclusion, a separation of biological cells labelled with magnetic microbeads is expected to be realized using the fabricated PDMS microchannel.

scholarly journals A Quantitative Study of the Secondary Acoustic Radiation Force on Biological Cells during Acoustophoresis

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 152 ◽  
Author(s):  
Davood Saeidi ◽  
Mohsen Saghafian ◽  
Shaghayegh Haghjooy Javanmard ◽  
Martin Wiklund
Keyword(s):  
Acoustic Radiation ◽  
Microfluidic Channel ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Ultrasonic Frequency ◽  
Biological Cells ◽  
Experimental Conditions ◽  
Ultrasonic Standing Wave ◽  
Radiation Forces ◽  
Silica Beads

We investigate cell-particle secondary acoustic radiation forces in a plain ultrasonic standing wave field inside a microfluidic channel. The effect of secondary acoustic radiation forces on biological cells is measured in a location between a pressure node and a pressure anti-node and the result is compared with theory by considering both compressibility and density dependent effects. The secondary acoustic force between motile red blood cells (RBCs) and MCF-7 cells and fixed 20 µm silica beads is investigated in a half-wavelength wide microchannel actuated at 2 MHz ultrasonic frequency. Our study shows that the secondary acoustic force between cells in acoustofluidic devices could play an important role for cell separation, sorting, and trapping purposes. Our results also demonstrate the possibility to isolate individual cells at trapping positions provided by silica beads immobilized and adhered to the microchannel bottom. We conclude that during certain experimental conditions, the secondary acoustic force acting on biological cells can dominate over the primary acoustic radiation force, which could open up for new microscale acoustofluidic methods.

Microelectrode Design in MEMS-Based DEP Cell Filtration Devices

2005 ◽  
Author(s):  
Mohammed J. Ahamed ◽  
Mohammad A. Rahman
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Dielectric Constant ◽  
Electric Field Intensity ◽  
Microfluidic Channel ◽  
Biological Cells ◽  
The Finite Element Method ◽  
Electrode Diameter ◽  
Cell Filtration ◽  
Simulation Results

This paper presents the design of a MEMS-based active DEP (dielectrophoresis) cell filtration microchip for manipulating and separating biological cells. Depending on the dielectric constant and polarizability, biological cells are either attracted to or repelled from the electrodes inside a microfluidic channel. Through the optimization of electrode geometries using the finite element method (FEM), it was found that circular electrodes are capable of producing a more uniform and larger gradient of the squared electric field intensity compared to electrodes of other shapes, such as square, diamond, or triangle, FEM numerical simulation results were also used to determine 50μm as the optimal circular electrode diameter and 25μm as the optimal gap between electrodes.

Design, Simulation and Fabrication of Polydimethylsiloxane (PDMS) Microchannel for Lab-on-Chip (LoC) Applications

2016 ◽  
Vol 819 ◽  
pp. 420-424
Author(s):  
Ummikalsom Abidin ◽  
Burhanuddin Yeop Majlis ◽  
Jumril Yunas
Keyword(s):  
Microfluidic Channel ◽  
Volumetric Flow Rate ◽  
Biological Cells ◽  
Element Analysis ◽  
Magnetic Separator ◽  
Lab On Chip ◽  
Pdms Microchannel ◽  
Reversible Bonding ◽  
On Chip ◽  
Microchannel Design

Microchannel of micron-to milimeter in dimension has been immensely used for fluid handling in transporting, mixing and separating biological cells in Lab-on-Chip (LoC) applications. In this paper, design, simulation and fabrication of Polydimethylsiloxane (PDMS) microfluidic channel are presented. The microchannel is designed with one inlet and outlet. A reservoir or chamber is proposed as an extra component in the microchannel design for ease of separating the intended biological cells as used in LoC magnetic separator and micro-incubator. Finite Element Analysis (FEA) shows laminar flow characteristic is maintained in the proposed microchannel design operating at volumetric flow rate between 0.5 to 1000 μL/min. In addition, pressure drop data across the microchannel are also been obtained from the FEA in determining the safe operation limit of the microchannel. The PDMS microchannels of two different chamber geometries have been successfully fabricated using replica molding technique from SU-8 negative photoresist mold. The fabricated SU-8 mold and the PDMS microchannel structure dimension are characterized using Scanning Electron Microscopy (SEM). Reversible bonding of PDMS microchannel layer and PDMS tubing layer has successfully accomplished by activating the PDMS surfaces using corona discharge. The preliminary testing of the microchannel confirmed its function for LoC continuous flow applications.

Improved micro-impedance spectroscopy to determine cell barrier properties

2020 ◽  
Vol 4 (3) ◽  
pp. 150-155 ◽  
Author(s):  
Md. Mehadi Hasan Sohag ◽  
Olivier Nicoud ◽  
Racha Amine ◽  
Abir Khalil-Mgharbel ◽  
Jean-Pierre Alcaraz ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Epithelial Cells ◽  
Lipid Bilayers ◽  
Cultured Cells ◽  
Cell Model ◽  
Measurement Techniques ◽  
Cell Monolayer ◽  
Microfluidic Channel ◽  
Small Surface ◽  
Resistance Pathway

AbstractThe goal of this study was to determine whether the Tethapod system, which was designed to determine the impedance properties of lipid bilayers, could be used for cell culture in order to utilise micro-impedance spectroscopy to examine further biological applications. To that purpose we have used normal epithelial cells from kidney (RPTEC) and a kidney cancer cell model (786-O). We demonstrate that the Tethapod system is compatible with the culture of 10,000 cells seeded to grow on a small area gold measurement electrode for several days without affecting the cell viability. Furthermore, the range of frequencies for EIS measurements were tuned to examine easily the characteristics of the cell monolayer. We demonstrate significant differences in the paracellular resistance pathway between normal and cancer kidney epithelial cells. Thus, we conclude that this device has advantages for the study of cultured cells that include (i) the configuration of measurement and reference electrodes across a microfluidic channel, and (ii) the small surface area of 6 parallel measurement electrodes (2.1 mm2) integrated in a microfluidic system. These characteristics might improve micro-impedance spectroscopy measurement techniques to provide a simple tool for further studies in the field of the patho-physiology of biological barriers.

Open-ended MEMS Probes for Dielectric Spectroscopy of Biological Cells at Radio Frequencies

PIERS Online ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 251-255 ◽  
Author(s):  
Hsin-Hung Li ◽  
Jen-Yu Jao ◽  
Ming-Kun Chen ◽  
Ling-Sheng Jang ◽  
Yi-Chu Hsu
Keyword(s):  
Dielectric Spectroscopy ◽  
Biological Cells ◽  
Radio Frequencies
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