Counterflow Rejection of Adsorbing Proteins for Characterization of Biomolecular Interactions by Temperature Gradient Focusing

2008 ◽  
Vol 80 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Matthew S. Munson ◽  
J. Mark Meacham ◽  
Laurie E. Locascio ◽  
David Ross
Keyword(s):  
Temperature Gradient ◽  
Biomolecular Interactions ◽  
Temperature Gradient Focusing

scholarly journals Application of temperature gradient gel electrophoresis to the characterization of a nitrifying bioaugmentation product

2003 ◽  
Vol 43 (2) ◽  
pp. 277-286 ◽  
Author(s):  
Melissa A. Fouratt ◽  
Jeremy S. Rhodes ◽  
Charles M. Smithers ◽  
Nancy G. Love ◽  
Ann M. Stevens
Keyword(s):  
Temperature Gradient ◽  
Gel Electrophoresis ◽  
Gradient Gel Electrophoresis ◽  
Temperature Gradient Gel Electrophoresis

Joule Heating Induced Temperature Gradient Focusing for Microfluidic Concentration of Samples

2010 ◽  
Author(s):  
Zhengwei Ge ◽  
Chun Yang
Keyword(s):  
Temperature Gradient ◽  
Electric Field ◽  
Joule Heating ◽  
Field Experiments ◽  
Dc Voltage ◽  
Sample Concentration ◽  
Great Achievement ◽  
Temperature Gradient Focusing ◽  
Concentration Enhancement ◽  
High Frequency Ac

Microfluidic concentration of sample species is achieved using the temperature gradient focusing (TGF) in a microchannel with a step change in the cross-section under a pure direct current (DC) field or a combined alternating current (AC) and DC electric field. Experiments were carried out to study the effects of applied voltage, buffer concentration and channel size on sample concentration in the TGF processes. These effects were analyzed and summarized using a dimensionless Joule number that is introduced in this study. In addition, Joule number effect in the Poly-dimethylsiloxane (PDMS)/PDMS microdevice was compared with the PDMS/Glass microdevice. A more than 450-fold concentration enhancement was obtained within 75 seconds in the PDMS/PDMS microdevice. Results also showed that the high frequency AC electric field which contributes to produce the temperature gradient and reduces the required DC voltage for the sample concentration. The lower DC voltage has generated slower electroosmotic flow (EOF), which reduces the backpressure effect associated with the finite reservoir size. Finally, a more than 2500-fold concentration enhancement was obtained within 14 minutes in the PDMS/PDMS microdevice, which was a great achievement in this TGF technique using inherent Joule heating effects.

Characterization of Poly(2-vinylpyridine) by Temperature Gradient Interaction Chromatography

2006 ◽  
Vol 39 (9) ◽  
pp. 3466-3468 ◽  
Author(s):  
Soojin Park ◽  
Taihyun Chang
Keyword(s):  
Temperature Gradient

Optothermal Analyte Manipulation With Temperature Gradient Focusing

2010 ◽  
Author(s):  
M. Akbari ◽  
M. Bahrami ◽  
D. Sinton
Keyword(s):  
Temperature Gradient ◽  
Heat Source ◽  
Optical System ◽  
Fluorescent Dye ◽  
Source Position ◽  
Video Projector ◽  
Temperature Gradient Focusing ◽  
Arbitrary Location ◽  
And Control ◽  
Preconcentration Method

An optothermal analyte preconcentration method is introduced in this work based on temperature gradient focusing. The present approach offers a flexible, noncontact technique for focusing and transporting of analytes. Here, we use a commercial video projector and an optical system to generate heat and control the heat source position, size and power. This heater is used to focus a sample model analyte, fluorescent dye, at an arbitrary location along the microchannel. Optothermal manipulation of the focused band was demonstrated by projecting a series of images with a moving light band.

Microfluidic concentration enhancement of bio-analyte by temperature gradient focusing via Joule heating by DC plus AC field: A numerical approach

2021 ◽  
pp. 1-17
Author(s):  
Amitava Dutta ◽  
Apurba Kumar Santra ◽  
Ranjan Ganguly
Keyword(s):  
Temperature Gradient ◽  
Joule Heating ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Numerical Approach ◽  
High Concentration ◽  
Buffer Solution ◽  
Temperature Gradient Focusing ◽  
Ac Field ◽  
Target Analyte

Abstract We present a detailed numerical analysis of electrophoresis induced concentration of a bio-analyte facilitated by temperature gradient focusing in a phosphate buffer solution via Joule heating inside a converging-diverging microchannel. The purpose is to study the effects of frequency of AC field and channel width variation on the concentration of target analyte. We tune the buffer viscosity, conductivity and electrophoretic mobility of the analyte such that the electrophoretic velocity of the analyte locally balances the electroosmotic flow of the buffer, resulting in a local build-up of the analyte concentration in a target region. An AC field is superimposed on the applied DC field within the microchannel in such a way that the back pressure effect is minimized, resulting in minimum dispersion and high concentration of the target analyte. Axial transport of fluorescein-Na in the phosphate buffer solution is controlled by inducing temperature gradient through Joule heating. The technique leverages the fact that the buffer's ionic strength and viscosity depends on temperature, which in turn guides the analyte transport. A numerical model is proposed and a finite element-based solution of the coupled electric field, mass, momentum, energy and species equations are carried out. Simulation predict peak of 670-fold concentration of fluorescein-Na is achieved. The peak concentration is found to increase sharply as the channel throat width, while the axial spread of concentrated analyte increases at lower frequency of AC field. The results of the work may improve the design of micro concentrator.

Study of Liquid-Metal Based Heating Method for Temperature Gradient Focusing Purpose

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
M. Gao ◽  
L. Gui ◽  
J. Liu
Keyword(s):  
Optimal Design ◽  
Temperature Gradient ◽  
Liquid Metal ◽  
Theoretical Analysis ◽  
Numerical Simulations ◽  
Microfluidic Channels ◽  
Heating Method ◽  
Electrical Heater ◽  
Temperature Gradient Focusing ◽  
A New Technique

Temperature gradient focusing (TGF) is a highly efficient focusing technique for the concentration and separation of charged analytes in microfluidic channels. The design of an appropriate temperature gradient is very important for the focusing efficiency. In this study, we proposed a new technique to generate the temperature gradient. This technique utilizes a microchannel filled with liquid-metal as an electrical heater in a microfluidic chip. By applying an electric current, the liquid-metal heater generates Joule heat, forming the temperature gradient in the microchannel. To optimize the temperature gradient and find out the optimal design for the TGF chip, numerical simulations on four typical designs were studied. The results showed that design 1 can provide a best focusing method, which has the largest temperature gradient. For this best design, the temperature is almost linearly distributed along the focusing microchannel. The numerical simulations were then validated both theoretically and experimentally. The following experiment and theoretical analysis on the best design also provide a useful guidance for designing and fabricating the liquid-metal based TGF microchip.

Implementation and characterization of fiber Bragg gratings linearly chirped by a temperature gradient

1994 ◽  
Vol 19 (23) ◽  
pp. 2027 ◽  
Author(s):  
Jocelyn Lauzon ◽  
Simon Thibault ◽  
Jean Martin ◽  
François Ouellette
Keyword(s):  
Temperature Gradient ◽  
Fiber Bragg Gratings ◽  
Bragg Gratings
Sign in / Sign up

Export Citation Format

Share Document