Experimental determination of trapping efficiency of optical tweezers

Cabrera, Humberto; Suárez-Vargas, José; López, Alejandro; Núñez, Héctor Hugo Cerecedo; Carvalho, Gustavo; Coceano, Giovanna; Cojoc, D.

doi:10.1080/09500839.2013.835078

Cited by 4 publications

(2 citation statements)

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“…In order to collect cells and particles in a confined geometry, several cell‐handling methods, including optical tweezers , chemical patterning , nano‐electrode arrays , microwell arrays , and combination of the aforementioned methods , have been developed. Especially, microwell arrays enable large scale arraying and high‐throughput measurements .…”

Section: Introductionmentioning

confidence: 99%

Dielectrophoresis assisted loading and unloading of microwells for impedance spectroscopy

et al. 2017

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Dielectric spectroscopy (DS) is a non-invasive, label-free, fast, and promising technique for measuring dielectric properties of biological cells in real time. We demonstrate a microchip that consists of electro-activated micro-well arrays for positive dielectrophoresis (pDEP) assisted cell capture, DS measurements, and negative dielectrophoresis (nDEP) driven cell unloading; thus, providing a high throughput cell analysis platform. To the best of our knowledge, this is the first microfluidic chip that combines electro-activated micro-wells and DS to analyze biological cells. Device performance is tested using Saccharomyces Cerevisiae (yeast) cells. DEP response of yeast cells is determined by measuring their Clausius-Mossotti (CM) factor using biophysical models in parallel plate micro-electrode geometry. This information is used to determine the excitation frequency to load and unload wells. Effect of yeast cells on the measured impedance spectrum was examined both experimentally and numerically. Good match between the numerical and experimental results establishes the potential use of the micro-chip device for extracting sub-cellular properties of biological cells in a rapid and non-expensive manner.

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Section: Introductionmentioning

confidence: 99%

Dielectrophoresis assisted loading and unloading of microwells for impedance spectroscopy

et al. 2017

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“…For our experimental case of interest, none of this information is readily available and may require additional complex measurements to obtain. Similarly, optical trap calibration methods involving measurements of the power spectrum 23,24 or scattering efficiencies [25][26][27] have only been experimentally verified using spherical objects. Consequently, alternative methods of calculating the applied force based on particle tracking have been developed.…”

Section: Introductionmentioning

confidence: 99%

Near real-time measurement of forces applied by an optical trap to a rigid cylindrical object

2014

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Abstract. An automated data acquisition and processing system is established to measure the force applied by an optical trap to an object of unknown composition in real time. Optical traps have been in use for the past 40 years to manipulate microscopic particles, but the magnitude of applied force is often unknown and requires extensive instrument characterization. Measuring or calculating the force applied by an optical trap to nonspherical particles presents additional difficulties which are also overcome with our system. Extensive experiments and measurements using well-characterized objects were performed to verify the system performance. © The Authors.Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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