Characterization of the Effect of Geometry on Single Cell Adhesion Strength Using a Microfluidic Device

2007 ◽  
Author(s):  
Kevin V. Christ ◽  
Kyle B. Williamson ◽  
Kristyn S. Masters ◽  
Kevin T. Turner
Keyword(s):  
Cell Adhesion ◽  
Single Cell ◽  
Adhesion Strength ◽  
Single Cells ◽  
Microfluidic Channel ◽  
Reynolds Numbers ◽  
Microfluidic Channels ◽  
Low Reynolds Numbers ◽  
Physiological Processes ◽  
Micropipette Manipulation

Cell adhesion plays a crucial role in a number of fundamental physiological processes and is important in the development of implantable biomaterials. Cell adhesion strength has previously been measured using a range of techniques, including population assays (e.g., centrifugation [1], hydrodynamic flow [2]) and single-cell methods (e.g., AFM [3], micropipette manipulation [4]). Population studies are unable to provide detailed information about individual cell behavior, while the single-cell methods are often time-consuming and difficult to perform. Microfluidic channels present a way to generate well-defined stress fields on cells [5]. The small dimensions of these channels result in low Reynolds numbers that allow for the generation of sufficiently large stresses to detach well-spread cells under laminar flow conditions. In the present work, a microfluidic channel was used to controllably load adhered single-cells to detachment and measure the adhesion strength. Using this assay, the effect of cell geometry on adhesion strength was investigated.

Adhesive Density of 11-Mercaptoundecanoic Acid (MUA) and Turnip Yellow Mosaic Virus (TYMV) in Microfluidic Channels

2009 ◽  
Author(s):  
Chia-Che Wu ◽  
Ping-Kuo Tseng ◽  
Meng-Jhu Hou ◽  
Ching-Hsiu Tsai
Keyword(s):  
Mosaic Virus ◽  
Food Poisoning ◽  
Microfluidic Channel ◽  
Reynolds Numbers ◽  
Detection Methods ◽  
Yellow Mosaic Virus ◽  
Microfluidic Channels ◽  
Turnip Yellow Mosaic Virus ◽  
Low Reynolds Numbers ◽  
Low Reynolds

Recently, there has been an increasing interest to develop rapid, reliable and low-concentration detection methods of micro-organisms involved in bioterrorism, food poisoning, and clinical problems. How to detect virus at concentration below the threshold will be challenging with respect to specificity, selectivity, and sensitivity. Among all parameters, sensitivity is probably the most critical consideration. If the sensitivity is not satisfied for real-time detection, researchers need to duplicate numerous numbers of viruses. However, it will substantially increase processing times and experimental hazard. To increase the sensitivity of virus sensors, this paper discusses how to increase the density of linkers and viruses on sensor’s surface in the microfluidic channels. In the future, researcher could use emerging technology, such as PT-PCR, QCM, C-V and I-V measurements, etc, to detect viruses on sensor’s surface. Usually microorganisms, molecules, or viruses in the fluidic environment are at very low Reynolds numbers because of tiny diameters. At very low Reynolds numbers, viscous forces of molecules and viruses will dominate. Those micro- or nanoparticles will stop moving immediately when flows cease and drag forces disappear. Of course, molecules and viruses are still subject to Brownian motion and move randomly. In order to increase the adhesion density of micro- and nanoparticles on sensor’s surface, designs of the flow movements in microfluidic channel is proposed. Adhesion density of linker 11-mercaptoundecanoic acid (MUA) and turnip yellow mosaic virus (TYMV) with specific quantum dots were measured by confocal microscope. Results show that TYMV and MUA layers disperse randomly by dipping method. Infusion rate, flow rate, and transverse flow could affect the adhesion densities of recognition layers on sensors’ surface. Adhesion densities of MUA and TYMV can be reached 70∼80% by microfluidic method to contrast just 10% by dipping method.

Improving Adhesion Density and Coverage Uniformity of Antibody-Antigen Binding on a Sensor Surface Using U-Type, T-Type and W-Type Microfluidic Devices

2011 ◽  
Author(s):  
Chia-Che Wu ◽  
Ping-Kuo Tseng ◽  
Ching-Hsiu Tsai
Keyword(s):  
Quantum Dots ◽  
Microfluidic Channel ◽  
Microfluidic Devices ◽  
Reynolds Numbers ◽  
Yellow Mosaic Virus ◽  
Fluorescent Intensity ◽  
Low Reynolds Numbers ◽  
Viscous Forces ◽  
Drag Forces ◽  
Low Reynolds

Usually microorganisms, molecules, or viruses in the fluidic environment are at very low Reynolds numbers because of tiny diameters. At very low Reynolds numbers, viscous forces of molecules and viruses will dominate. Those micro- or nanoparticles will stop moving immediately when flows cease and drag forces disappear, those phenomena were discovered by the fluorescent particle experiment. Of course, molecules and viruses are still subject to Brownian motion and move randomly. In order to increase the adhesion density of micro- and nanoparticles on sensor’s surface, designs of the flow movements in microfluidic channel is proposed. Adhesion density of linker 11-mercaptoundecanoic acid (MUA) and Turnip yellow mosaic virus (TYMV) with specific quantum dots were measured by confocal microscope. Fluorescent intensity and coverage of quantum dots are used to identify the adhesion density quantitatively. Results show that TYMV and MUA layers disperse randomly by dipping method. Fluorescent intensity of quantum dots; i.e. relative to the amount of MUA and TYMV; were 2.67A.U. and 19.13A.U., respectively, in W-type microfluidic devices to contrast just 1.00A.U. and 1.00A.U., respectively, by dipping method. Coverage of MUA and TYMV were 80∼90% and 70∼90%, respectively, in W-type microfluidic channel to contrast just 20∼50% and 0∼10%, respectively, by dipping method.

scholarly journals Selective Retrieval of Individual Cells from Microfluidic Arrays Combining Dielectrophoretic Force and Directed Hydrodynamic Flow

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 322
Author(s):  
Pierre-Emmanuel Thiriet ◽  
Joern Pezoldt ◽  
Gabriele Gambardella ◽  
Kevin Keim ◽  
Bart Deplancke ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Microfluidic System ◽  
Transcriptional Analysis ◽  
Molecular Profile ◽  
Cell Phenotype ◽  
Pneumatic Valves ◽  
On Chip

Hydrodynamic-based microfluidic platforms enable single-cell arraying and analysis over time. Despite the advantages of established microfluidic systems, long-term analysis and proliferation of cells selected in such devices require off-chip recovery of cells as well as an investigation of on-chip analysis on cell phenotype, requirements still largely unmet. Here, we introduce a device for single-cell isolation, selective retrieval and off-chip recovery. To this end, singularly addressable three-dimensional electrodes are embedded within a microfluidic channel, allowing the selective release of single cells from their trapping site through application of a negative dielectrophoretic (DEP) force. Selective capture and release are carried out in standard culture medium and cells can be subsequently mitigated towards a recovery well using micro-engineered hybrid SU-8/PDMS pneumatic valves. Importantly, transcriptional analysis of recovered cells revealed only marginal alteration of their molecular profile upon DEP application, underscored by minor transcriptional changes induced upon injection into the microfluidic device. Therefore, the established microfluidic system combining targeted DEP manipulation with downstream hydrodynamic coordination of single cells provides a powerful means to handle and manipulate individual cells within one device.

scholarly journals Separations-encoded microparticles for single-cell western blotting

2019 ◽  
Author(s):  
Burcu Gumuscu ◽  
Amy Elizabeth Herr
Keyword(s):  
Single Cell ◽  
Single Cells ◽  
Thin Sheet ◽  
Protein Electrophoresis ◽  
Microfluidic Channels ◽  
Fluorescence Signal ◽  
Analytical Sensitivity ◽  
Planar Array ◽  
Single Cell Isolation ◽  
Mechanical Release

Direct measurement of proteins from single cells has been realized at the microscale using microfluidic channels, capillaries, and semi-enclosed microwell arrays. Although powerful, these formats are constrained, with the enclosed geometries proving cumbersome for multistage assays, including electrophoresis followed by immunoprobing. We introduce a hybrid microfluidic format that toggles between a planar microwell array and a suspension of microparticles. The planar array is stippled in a thin sheet of polyacrylamide gel, for efficient single-cell isolation and protein electrophoresis of hundreds-to-thousands of cells. Upon mechanical release, array elements become a suspension of separations-encoded microparticles for more efficient immunoprobing due to enhanced mass transfer. Dehydrating microparticles offer improved analytical sensitivity owing to in-gel concentration of fluorescence signal for high-throughput single-cell targeted proteomics.

scholarly journals Single cell adhesion strength assessed with variable-angle total internal reflection fluorescence microscopy

2017 ◽  
Vol 4 (3) ◽  
pp. 438-450 ◽  
Author(s):  
Marcelina Cardoso Dos Santos ◽  
◽  
Cyrille Vézy ◽  
Hamid Morjani ◽  
Rodolphe Jaffol ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Fluorescence Microscopy ◽  
Single Cell ◽  
Adhesion Strength ◽  
Total Internal Reflection ◽  
Internal Reflection ◽  
Total Internal Reflection Fluorescence ◽  
Variable Angle

scholarly journals Single-cell adhesion strength and contact density drops in the M phase of cancer cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rita Ungai-Salánki ◽  
Eleonóra Haty ◽  
Tamás Gerecsei ◽  
Barbara Francz ◽  
Bálint Béres ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Single Cell ◽  
Cancer Cells ◽  
Adhesion Strength ◽  
Adhesion Force ◽  
Single Cell Level ◽  
Cell Level ◽  
Contact Density ◽  
M Phase ◽  
Tissue Cells

AbstractThe high throughput, cost effective and sensitive quantification of cell adhesion strength at the single-cell level is still a challenging task. The adhesion force between tissue cells and their environment is crucial in all multicellular organisms. Integrins transmit force between the intracellular cytoskeleton and the extracellular matrix. This force is not only a mechanical interaction but a way of signal transduction as well. For instance, adhesion-dependent cells switch to an apoptotic mode in the lack of adhesion forces. Adhesion of tumor cells is a potential therapeutic target, as it is actively modulated during tissue invasion and cell release to the bloodstream resulting in metastasis. We investigated the integrin-mediated adhesion between cancer cells and their RGD (Arg-Gly-Asp) motif displaying biomimetic substratum using the HeLa cell line transfected by the Fucci fluorescent cell cycle reporter construct. We employed a computer-controlled micropipette and a high spatial resolution label-free resonant waveguide grating-based optical sensor calibrated to adhesion force and energy at the single-cell level. We found that the overall adhesion strength of single cancer cells is approximately constant in all phases except the mitotic (M) phase with a significantly lower adhesion. Single-cell evanescent field based biosensor measurements revealed that at the mitotic phase the cell material mass per unit area inside the cell-substratum contact zone is significantly less, too. Importantly, the weaker mitotic adhesion is not simply a direct consequence of the measured smaller contact area. Our results highlight these differences in the mitotic reticular adhesions and confirm that cell adhesion is a promising target of selective cancer drugs as the vast majority of normal, differentiated tissue cells do not enter the M phase and do not divide.

Lateral Migration of Neutrally-Buoyant Particles in a Square Microchannel at Low Reynolds Numbers

2009 ◽  
Author(s):  
Byung Rae Cho ◽  
Young Won Kim ◽  
Jung Yul Yoo
Keyword(s):  
Reynolds Numbers ◽  
Spherical Particles ◽  
Channel Cross Section ◽  
Microfluidic Channels ◽  
Lateral Migration ◽  
Low Reynolds Numbers ◽  
Low Reynolds ◽  
Square Microchannel ◽  
External Forces ◽  
Neutrally Buoyant

Lateral migration of particles has drawn a lot of attention in suspension community for the last 50 years. Since there is no need for extra external forces, lateral migration of particles plays an important role in constructing microfluidic devices in diverse engineering applications. In this paper, an experimental study on lateral migration of neutrally-buoyant spherical particles transported through a square microchannel is carried out using a fluorescent microscope at low Reynolds numbers. Fluorescent microspheres with diameters of d = 6 μm, 10 μm, and 16 μm are adopted as the test particles, which yield channel-to-particle size ratios of 13.3, 8 and 5, respectively. Spatial distributions of the particles in dilute suspension are visualized at different Reynolds numbers. It is shown that particles are uniformly distributed over the channel cross-section at relatively low Reynolds numbers. As the Reynolds number increases, however, particles migrate inward from the wall and away from the central axis of the channel, so that consequently they accumulate at an equilibrium position, exhibiting the so-called “tubular pinch effect”, first observed by Segre´ and Silberberg as early as in 1962. Experimental results obtained in this work offer design rules for microfluidic channels that play important roles of particle separation or particle focusing.

Optical guiding-based cell focusing for Raman flow cell cytometer

The Analyst ◽  
2018 ◽  
Vol 143 (11) ◽  
pp. 2648-2655 ◽  
Author(s):  
Ravi Shanker Verma ◽  
Sunita Ahlawat ◽  
Abha Uppal
Keyword(s):  
Single Cell ◽  
Spectroscopic Analysis ◽  
Single Cells ◽  
Microfluidic Channel ◽  
Flow Cell ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Analysis

We report the use of an optical guiding arrangement generated in a microfluidic channel to produce a stream of single cells in a line for single-cell Raman spectroscopic analysis.

Sign in / Sign up

Export Citation Format

Share Document