Capillary electrophoresis characterisation of a rapid prototyped PMMA chip for particle analysis

Màster en Nanociència i NanotecnologiaA rapid and cheap method has been developed for the fabrication of a capillary electrophoresis chip for the preliminary characterization of particles. The microfluidic chips were fabricated using polymethyl methacrylate (PMMA) with integrated platinum electrodes without the need of using high technology microfabrication techniques. The chips were characterized using electroosmotic flow (EOF) with different channel treatments. The electrodes were characterised with impedance and conductivity measurements using both static and electrophoretic flow, respectively. Nine micron diameter particles were detected and their electrophoretic mobility determined using capillary electrophoresis and conductivity detection

An investigation into the sample preparation procedure and analysis of cyanoacrylate adhesives using capillary electrophoresis

In this study, the trace acid profile of cyanoacrylate adhesives was studied using capillary electrophoresis. Liquid–liquid extraction was employed as the sample preparation step before separation by capillary electrophoresis. The solubility of the adhesives was investigated using various organic solvents, e.g. hexane and dichloromethane, and chloroform was determined to be the optimum solvent as it enabled the full dissolution of the adhesive. A comprehensive stability study was performed over a 3-year period and results indicate that the adhesives were stable for 2 years after which their stability and performance degraded

Strongly nonlinear waves in capillary electrophoresis

In capillary electrophoresis, sample ions migrate along a micro-capillary filled with a background electrolyte under the influence of an applied electric field. If the sample concentration is sufficiently high, the electrical conductivity in the sample zone could differ significantly from the background.Under such conditions, the local migration velocity of sample ions becomes concentration dependent resulting in a nonlinear wave that exhibits shock like features. If the nonlinearity is weak, the sample concentration profile, under certain simplifying assumptions, can be shown to obey Burgers' equation (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, 72(8), pg. 2047) which has an exact analytical solution for arbitrary initial condition.In this paper, we use a numerical method to study the problem in the more general case where the sample concentration is not small in comparison to the concentration of background ions. In the case of low concentrations, the numerical results agree with the weakly nonlinear theory presented earlier, but at high concentrations, the wave evolves in a way that is qualitatively different.Comment: 7 pages, 5 figures, 1 Appendix, 2 videos (supplementary material

Kapilarna elektroforeza u farmaciji

Capillary electrophoresis is a new separation technique. It is an analytical technique that usually complements or replaces high performance liquid chromatography. Basic principle of the technique is the migration of charged species under applied electric field towards one of the electrodes through a narrow capillary filled with electrolyte solution. Main advantages over other chromatographic methods are short analysis time, high efficiency, small sample and solvent volumes, low costs, simplicity and ecological acceptability. Capillary electrophoresis has several modes of separation which allows analysis of different types of analytes. Capillary electrophoresis has found its application in the drug analysis of large molecules like proteins, peptides and nucleic acids, small organic molecules such as drugs, hormones, plant metabolites, food product ingredients, small inorganic ions etc. It is a method of choice when rapid results are needed. Capillary electrophoresis has become the predominant technique for the analysis of both basic and chiral pharmaceuticals, it is unavoidable in biotechnology and promises to be a valuable tool in troubleshooting in proteome-wide analysis, DNA sequencing and genotyping. Despites of all advantages and application possibilities, capillary electrophoresis is still not enough explored and used in routine analysis. A review of different capillary electrophoresis techniques principles and applications in pharmacy is presented in this article

Capillary Electrophoresis in Nanotechnologies versus Nanotechnologies in Capillary Electrophoresis

Nanomaterials are attracting an interest of many researches. All this attention is due the unique physical and chemical properties of nanomaterials differing significantly from the bulk materials mainly due to their size in range of nanometers. Capillary electrophoresis (CE) is a powerful, well-established analytical technique that provides numerous valuable benefits over other separation methods including high-performance liquid chromatography. The connection between CE and nanotechnology can be approached by two strategies: (i) CE analysis of nanomaterials and (ii) nanomaterials for CE improvement. The first perspective focuses on uses of CE as a method for characterization employed during nanomaterial production and modification as well as for monitoring their properties and interactions with other molecules. The second viewpoint deals with applications of nanomaterials for improving CE performance, mainly by enhancing efficiency of separation using nanomaterials as a stationary or pseudo-stationary phase and by enhancing detection sensitivity and/or selectivity in both optical and electrochemical detection. Moreover, applications of nanomaterials for sample preparation before CE analysis will be mentioned. This chapter aims at highlighting the symbiosis of CE and nanotechnology as a combination of modern, progressive field with well-known and reliable analytical method

Microchip Capillary Electrophoresis

For the study of neuromodulation in Cancer borealis we have designed a microfluidic device to separate and detect bioamine concentrations with a high temporal resolution. Our goal is to use this device to measure the concentration of continuous bioamine microdialysis samples directly from the pericardial cavity (the area surrounding the heart) of Cancer borealis. The microfluidic device that we designed is made from polydimethylsiloxane (PDMS) and exhibits an off-channel configuration of capillary electrophoresis (CE) by incorporating micellar electrokinetic chromatography (MEKC). CE is used to separate bioamines based on charge and size due to the applied electrical potential. In the off-channel configuration, the potential is applied across the separation channel and grounded by the palladium decoupler, which lies just before the detector. Microchip CE is advantageous because it uses small amounts of analyte and completes fast run times. We will use MEKC to separate dopamine and octopamine, since they are structural isomers, by their difference in affinity to sodium dodecyl sulfate (SDS) micelles. This results in different elution times for dopamine and octopamine. We were able to drive the fluid in the correct direction. The creation of this device has valuable implications, allowing for baseline concentrations of neuromodulators with the Cancer borealis to be established. The effect of different stimuli on these crabs can then be more accurately determined

HiTRACE-Web: an online tool for robust analysis of high-throughput capillary electrophoresis

To facilitate the analysis of large-scale high-throughput capillary electrophoresis data, we previously proposed a suite of efficient analysis software named HiTRACE (High Throughput Robust Analysis of Capillary Electrophoresis). HiTRACE has been used extensively for quantitating data from RNA and DNA structure mapping experiments, including mutate-and-map contact inference, chromatin footprinting, the EteRNA RNA design project and other high-throughput applications. However, HiTRACE is based on a suite of command-line MATLAB scripts that requires nontrivial efforts to learn, use, and extend. Here we present HiTRACE-Web, an online version of HiTRACE that includes standard features previously available in the command-line version as well as additional features such as automated band annotation and flexible adjustment of annotations, all via a user-friendly environment. By making use of parallelization, the on-line workflow is also faster than software implementations available to most users on their local computers. Free access: http://hitrace.or

HiTRACE: High-throughput robust analysis for capillary electrophoresis

Motivation: Capillary electrophoresis (CE) of nucleic acids is a workhorse technology underlying high-throughput genome analysis and large-scale chemical mapping for nucleic acid structural inference. Despite the wide availability of CE-based instruments, there remain challenges in leveraging their full power for quantitative analysis of RNA and DNA structure, thermodynamics, and kinetics. In particular, the slow rate and poor automation of available analysis tools have bottlenecked a new generation of studies involving hundreds of CE profiles per experiment. Results: We propose a computational method called high-throughput robust analysis for capillary electrophoresis (HiTRACE) to automate the key tasks in large-scale nucleic acid CE analysis, including the profile alignment that has heretofore been a rate-limiting step in the highest throughput experiments. We illustrate the application of HiTRACE on thirteen data sets representing 4 different RNAs, three chemical modification strategies, and up to 480 single mutant variants; the largest data sets each include 87,360 bands. By applying a series of robust dynamic programming algorithms, HiTRACE outperforms prior tools in terms of alignment and fitting quality, as assessed by measures including the correlation between quantified band intensities between replicate data sets. Furthermore, while the smallest of these data sets required 7 to 10 hours of manual intervention using prior approaches, HiTRACE quantitation of even the largest data sets herein was achieved in 3 to 12 minutes. The HiTRACE method therefore resolves a critical barrier to the efficient and accurate analysis of nucleic acid structure in experiments involving tens of thousands of electrophoretic bands.Comment: Revised to include Supplement. Availability: HiTRACE is freely available for download at http://hitrace.stanford.ed