Lab-on-a-Chip Application: Microfab-less Microfluidics for a Portable Hybrid Microchip-Capillary Electrophoresis DeviceMatthew T. Gordon and Carlos D. Garcia, University of Texas at San Antonio, San Antonio, TX
Microfluidic devices, with their potential for portability and rapid analysis times, can bring cost-effective flexibility to modern analytical chemistry applications. However, the design and fabrication of microchips can involve trade-offs between cost, flexibility of configuration, and ideal surface properties or performance. To circumvent these drawbacks, we have developed a hybrid platform consisting of simple microfabricated … Read more
Applying Voltage to a Channel in a Microfluidic Chip
Platinum wire electrodes are commonly used to apply voltage to a fluidic channel. Although the approach is relatively simple, proper preparation of the electrode is very important to prevent field concentrations in the channels. Field concentrations can cause a multitude of problems, including bubble formation, cell lysing, localized heating, chemical reactions, and clogging of channels. … Read more
Lab-on-a-Chip Application: Circulating Tumor Cell Immuncapture AutomationJulia Wang, Erica D. Pratt, and Brian J. Kirby, Cornell University
The manipulation of biological samples for diagnostic purposes requires reproducibility and simplicity to be useful in practice. As microfluidic devices transition towards use in medical diagnostics, traditional handheld syringe pumps can be too bulky and laborious for medical procedures that require quick turnaround times. Here, we discuss the evaluation of a portable breadboard platform that … Read more
Field Amplified Sample Stacking (FASS) for Sample Concentration in a NanochannelElizaveta Davies, Lesa Bishop, Adam Lucio, Jackson Travis del Bonis-O'Donnell, Sumita Pennathur, University of California, Santa Barbara; Yolanda Fintschenko, LabSmith, Inc.
A ubiquitous problem in analytical chemistry is the push to increase signal-to-noise (S/N) and to lower the limits of detection (LOD) for many sample separation methods. Low S/N is typically due to the inherent low concentration of the sample in the system and the band-broadening of the sample in dead volumes of the analytical system. … Read more
Performing an Electrokinetic Gated Injection in a NanochannelElizaveta Davies, Lesa Bishop, Adam Lucio, Travis del Bonis O'Donnell, Sumita Pennathur, University of California, Santa Barbara; Yolanda Fintschenko, LabSmith, Inc.
The microfluidic chip platform offers an advantage for electrokinetic chemical separations by eliminating the dead volume normally encountered with tubing connections. In order to capitalize on this advantage, sample injections must be performed on chip. The gated injection loads a variable injection volume by controlling velocity and injection time. The gated injection controls plug size … Read more
Making a Pinched Microfluidic Injection with the LabSmith LabPackage-Making a Microfluidic Injection on a ChipYolanda Fintschenko and Kirsten Pace LabSmith, Inc.
LabSmith’s LabPackage makes it easy to build, control and monitor simple and complex microfluidic manipulations. This experiment was designed to help you train your laboratory team and test competency on performing a pinched electrokinetic microfluidic injection techniques. It can also be used to test equipment, chips and reagents to ensure that they are working properly. … Read more
LabSmith Microparticle Image Velocimetry for Improving Dielectrophoretic Concentrator Using the LabSmith LabPackageJosé I. Martinez-López, Hector Moncada-Hernández, Javier L. Baylon-Cardiel, Sergio O. Martinez-Chapa, Tecnológico de Monterrey (Monterrey NL, Mexico) Blanca H. Lapizco-Encinas, CINVESTAV-Monterrey (Apodaca NL, Mexico), and Yolanda Fintschenko, LabSmith.
Sample preparation is a bottleneck for protein, cell and nucleic acid analysis, regardless of the analytical technique used. An important, and tedious, preparation step is selective concentration of the target of interest, particularly when target abundance is low. One approach is insulator-based dielectrophoresis, or iDEP, in which insulators, often etched in glass or stamped in … Read more
Controlling On-Chip Gradient Elution Microchannel Electrochromatography Using the LabSmith HVS448Michael W.L.Watson, Jared M. Mudrik and Aaron R. Wheeler, University of Toronto, and Yolanda Fintschenko, LabSmith.
Separations of complex peptide mixtures can take too long to elute without the ability to apply a solvent gradient. One solution for applying a gradient is called Microchannel Electrochromatography, or MEC. In reversed phase MEC buffers with aqueous and organic components comprise the mobile phase of a separation through a solid and porous stationary phase … Read more
Microfluidic Polyacrylamide Gel Electrophoresis with In-situ Immunoblotting for Native Protein AnalysisHe, M.; Herr, A.E.
He, M.; Herr, A.E. “Microfluidic Polyacrylamide Gel Electrophoresis with In-situ Immunoblotting for Native Protein Analysis.” Analytical Chemistry, 2009, 81, 8177-84. Abstract We introduce an automated immunoblotting method that reports protein electrophoretic mobility and identity in a single streamlined microfluidic assay. Native polyacrylamide gel electrophoresis (PAGE) was integrated with subsequent in situ immunoblotting. Integration of three … Read more
Prediction of trapping zones in an insulator-based dielectrophoretic deviceJavier L. Baylon-Cardiel , Blanca H. Lapizco-Encinas , Claudia Reyes-Betanzo , Ana V. Chávez-Santoscoy and Sergio O. Martínez-Chapa
Baylon-Cardiel, J.L.; Lapizco-Encinas,B.L.;Reyes-Betanzo,C.; Chavez-Santoscoy,A.V.; Martınez-Chapa, S.O. Prediction of trapping zones in an insulator-based dielectrophoretic device Lab-on-a-Chip, 2009, 9, 2896–2901. Abstract A mathematical model is implemented to study the performance of an insulator-based dielectrophoretic device. The geometry of the device was captured in a computational model that solves Laplace equation within an array of cylindrical insulating … Read more
Gradient elution in micro channel electrochromatographyWatson, M.W.L.; Mudrik, J.M.;Wheeler,A.R
Watson, M.W.L.; Mudrik, J.M.;Wheeler,A.R., Gradient elution in micro channel electrochromatography, Anal.Chem., 2009, 81, 3851-3857. Abstract There is great interest in using microfluidic channels packed with a stationary phase for chemical separations of complex mixtures. A key advantage of such techniques is the use of electroosmotic flow (EOF), controlled simply by applying electrical potentials between reservoirs. … Read more
Characterization of electrokinetic mobility of microparticles in order to improve dielectrophoretic concentrationJosé I. Martínez-López, Héctor Moncada-Hernández, Javier L. Baylon-Cardiel, Sergio O. Martínez-Chapa, Marco Rito-Palomares and Blanca H. Lapizco-Encinas
Martínez-López , J.I. ; Moncada-Hernández, H.;. Baylon-Cardiel, J. L.; Martínez- Chapa, S. O.; Rito-Palomares, M. ; Lapizco-Encinas, B.H., Characterization of electrokinetic mobility of microparticles in order to improve dielectrophoretic concentration, Anal Bioanal. Chem. 2009,394, 293–302. Abstract Insulator-based dielectrophoresis (iDEP), an efficient technique with great potential for miniaturization, has been successfully applied for the manipulation of … Read more
Protein manipulation with insulator-based dielectrophoresis and direct current electric fieldsBlanca H. Lapizco-Encinas, Sandra Ozuna-Chacón, Marco Rito-Palomares
Lapizco-Encinas, B.H.; Ozuna-Chaco´, S.; Rito-Palomares, M.; Protein manipulation with insulator-based dielectrophoresis and direct current electric fields, J.Chrom. A, 2008, 1206, 45–51. Abstract The present study demonstrates the manipulation of protein particles employing insulator-baseddielectrophoresis (iDEP) and directcurrent (d.c.) electricfields. Fluorescently labeled bovine serum albumin (BSA) protein particles were concentrated inside a microchannel that contained an array … Read more