ELECTROPHORESIS最新文献

{"title":"Obituary for Professor Dr. Joachim Klose to be Published in Electrophoresis.","authors":"","doi":"10.1002/elps.8118","DOIUrl":"https://doi.org/10.1002/elps.8118","url":null,"abstract":"","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143566414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dielectrophoresis Low and High Crossover Frequencies of Cancerous Exosomes.","authors":"Michihiko Nakano, Ryu Nakabayashi, Rie Koyama, Masafumi Inaba, Junya Suehiro","doi":"10.1002/elps.8128","DOIUrl":"https://doi.org/10.1002/elps.8128","url":null,"abstract":"<p><p>Exosomes, which constitute a subclass of extracellular vesicles found in various body fluids, play a crucial role in intercellular communication. Exosomes consist of matter derived from their host, such as nucleic acids, proteins, and membrane proteins. Cancer cell-derived exosomes have cancer-specific molecules and are found in the body fluids. As such, they are highly useful in liquid biopsies for cancer diagnosis. For diagnosis, rapid and simple determination of the sampled exosomes is important. Dielectrophoresis (DEP) manipulation has the potential for use in liquid biopsies. DEP behavior based on variations in exosomes has not been well investigated. In this study, the dielectrophoretic characteristics of exosomes derived from four cancer cell lines were investigated: MCF-7, PC-3, HT-29, and COLO 201. The DEP crossover frequencies of these exosomes were determined by directly observing their DEP behaviors at various suspension medium conductivities. Each exosome type exhibited distinct dielectrophoretic characteristics, with significant differences in the lower crossover frequencies linked to variations in the membrane properties and inner conductivity. A single-shell dielectric model was used to estimate the dielectric and physical parameters of the exosomes, aligning with the experimental results. These findings highlight the potential of DEP for specific exosome separation, enabling rapid and simple exosome-based liquid biopsies for cancer diagnosis.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143566381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simple and Convenient Three-Electrode Layout for Real-Time Electrorotation Measurement Upon Chemical Stimulation.","authors":"Masato Suzuki, Ryoga Yamada, Yuki Imou, Yushi Isozaki, Tomoyuki Yasukawa","doi":"10.1002/elps.8121","DOIUrl":"https://doi.org/10.1002/elps.8121","url":null,"abstract":"<p><p>We developed a novel electrorotation (ROT) device featuring a microwell array with three electrodes. This device allows to monitor the increase in membrane capacitance of cells subjected to chemical stimulation. The microwell array is integrated into the bottom of a fluidic channel and holds rotating cells during stimulation with a solution containing a chemical agent. Positive dielectrophoresis (p-DEP) effectively traps cells in microwells, whereas negative DEP (n-DEP) facilitates the rapid formation of single-cell presence. Alternating current (AC) voltages with a 120° phase shift applied across the three electrodes enable vertical and simultaneous rotation of cells. We observed a peak in rotation rate as a function of applied frequency, with the frequency spectrum shifting to lower frequencies as membrane capacitance increased. A positive correlation was identified between rotation rate and membrane capacitance, so monitoring in the low-frequency range is advantageous. Although n-DEP at lower frequencies risks removing cells from microwells, the continuous monitoring of the ROT rate during chemical stimulation was achieved by regulating the height of the ROT center of cells. We demonstrated the monitoring of membrane capacitance increase induced by Ca²⁺ influx from ionomycin. This simple configuration facilitates statistical analysis of ROT rates without fluorescent labeling, making it suitable for label-free assessments of white blood cells' responses to stimuli.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143515027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Contents: Electrophoresis 3–4'25","authors":"","doi":"10.1002/elps.202570022","DOIUrl":"https://doi.org/10.1002/elps.202570022","url":null,"abstract":"","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"46 3-4","pages":"131-132"},"PeriodicalIF":3.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial Board: Electrophoresis 3–4'25","authors":"","doi":"10.1002/elps.202570021","DOIUrl":"https://doi.org/10.1002/elps.202570021","url":null,"abstract":"","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"46 3-4","pages":"129-130"},"PeriodicalIF":3.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elps.202570021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design Guidelines of Free-Flow Counterflow Gradient Focusing Device for Protein Fractionation.","authors":"Matthew Courtney, Oscar Manuel Carreno-Molina, Carolyn L Ren","doi":"10.1002/elps.8106","DOIUrl":"https://doi.org/10.1002/elps.8106","url":null,"abstract":"<p><p>Free-flow counterflow gradient focusing (FF-CGF) is a promising tool for protein fractionation. This work establishes guidelines to construct an FF-CGF system suitable for preparative applications. Numerical and analytical computations are undertaken to investigate design parameters, including device geometry, flow conditions, sample concentration, and applied voltage. This collective information serves as a design tool to guide the fabrication of the device, which, in this case, is constructed from polymethyl methacrylate (PMMA) and double-sided tape. Furthermore, the design tool also supports device operation and provides insights into the expected resolution and throughput. Experimental results, which demonstrated the ability of the designed chip to generate a uniform counterflow gradient while separating small molecules and proteins, validated the accuracy of the design guidelines.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of a cIEF Fractionation Workflow for Offline MS Analysis of Charge Variants of the Monoclonal Antibody Matuzumab","authors":"Antonia Wittmann,&nbsp;Yannick Wilke,&nbsp;Nicolas Grammel,&nbsp;Hermann Wätzig","doi":"10.1002/elps.8108","DOIUrl":"10.1002/elps.8108","url":null,"abstract":"<p>Biological drugs like monoclonal antibodies require careful analysis and characterization to ensure product quality, safety, and efficacy. Charge variants of the molecule are of key interest and are analyzed using imaged capillary isoelectric focusing (icIEF). However, deeper characterization of these variants poses challenges. Two workflows for their characterization exist: an ion-exchange chromatography method for variant collection before mass spectrometry (MS) analysis, which is labor-intensive, and direct coupling of CE to MS, which allows detailed structural characterization but has limitations, for example, due to incompatibilities with ES ionization using high BGE concentrations. This study evaluates a platform that fractionates charge variants for offline MS analysis. The suitability of a procedure in which analytical icIEF methods are converted into preparative cIEF fractionation methods by increasing the sample concentration and adding 20 mM arginine as a cathodic spacer was tested. After chemical mobilization and fraction collection, the identity of the fractions was determined by fluorescence measurement and reinjection of the protein-containing fractions, using the previously developed analytical icIEF method. MS was subsequently performed. The general suitability of the workflow was demonstrated using Matuzumab. Transferring the analytical method from a concentration of 0.2 to 1.2 mg/mL in fractionation yielded an identical number of peaks and visually comparable peak profiles. The preparative separation took 50 min, with an additional 25 min for mobilization and 45 s per fraction collection, totaling approximately 2.5 h. Verification of charge variant isolation was straightforward via analytical icIEF. Following fractionation, MS allowed for the identification of the main peaks. Preliminary results with other antibodies indicated that the concentration range for MS experiments needs further investigation. Future work will aim to optimize sensitivity, selectivity, analysis time, and reproducibility.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"46 3-4","pages":"240-249"},"PeriodicalIF":3.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elps.8108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulation Noise and Its Significant Impact on the Dielectrophoretic Motion of Particles Near the Electrode Edges.","authors":"Aaditya Venkatesha Babu Bangaru, Stuart J Williams","doi":"10.1002/elps.8115","DOIUrl":"https://doi.org/10.1002/elps.8115","url":null,"abstract":"<p><p>Dielectrophoresis (DEP) has been extensively researched over the years for filtration, separation, detection, and collection of micro/nano/bioparticles. Numerical models have historically been employed to predict particle trajectories in three-dimensional (3D) DEP systems, but a common issue arises due to inherent noise near the edges of electrodes due to electric potential discontinuity, specifically when calculating electric field and gradient of electric field-squared, <math> <semantics> <mrow><mrow><mo>∇</mo> <mo>|</mo> <mi>E</mi></mrow> <msup><mo>|</mo> <mn>2</mn></msup> </mrow> <annotation>$nabla |E{|^2}$</annotation></semantics> </math> . This noise can be reduced to a certain extent with a finer mesh density but results near the electrode edge still have significant error. Realizing the importance of particle-electrode edge interactions prevalent in positive DEP systems, analytical solutions given by Sun et al. was incorporated to demonstrate an improved 3D model of interdigitated electrodes. The results of electric field and gradient of electric field-squared of the numerical model and the improved analytical 3D model were compared, within a simulation space of 50 µm height, 10 µm width, and 50 µm length with interdigitated electrodes of the same width and gap of 10 µm. The DEP particle trajectory error due to the noise was quantified for different particle sizes at various heights above the electrode edge. For example, at 5 V_rms, a trapped 500 nm particles exhibited a velocity error of 10⁴ µm/s (it should have been zero).</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced Particle Trap: Design and Simulation of Pillar-Based Contactless Dielectrophoresis Microfluidic Devices","authors":"Peyman Torky Harchegani,&nbsp;Mohsen Mashhadi Keshtiban,&nbsp;Mahdi Moghimi Zand,&nbsp;Zahra Azizi","doi":"10.1002/elps.202400110","DOIUrl":"10.1002/elps.202400110","url":null,"abstract":"<div>\u0000 \u0000 <p>Contactless and conventional dielectrophoresis (DEP) microfluidic devices are extensively utilized in lab-on-a-chip applications, particularly for cell isolation and analysis. Nonetheless, these devices typically operate at low throughput and require high applied voltages, posing limitations for microfluidic cell isolation and separation. Addressing these challenges, this study explores the utilization of diverse micro-pillar geometries within the microfluidic device to augment THP-1 cell trapping efficiency numerically using FEM modeling. Furthermore, the simulations examine the influence of pillar gap and quantity on cell trapping efficiency in a contactless DEP device. Notably, elliptical pillars demonstrate superior cell trapping efficiency at elevated flow rates compared to alternative configurations, making the microchip more amenable for high-throughput cell separation, trapping, and isolation applications. Remarkably, employing elliptical pillars in a contactless DEP microfluidic chip yields nearly 100% cell trapping efficiency at higher flow rates. Ellipse configuration showed 122% higher cell trap efficiency at the maximum flowrate compare to the previous study with circular configuration. Additionally, it is observed that reducing the gap between pillars correlates with enhanced cell trapping efficiency. Simulation outcomes indicate that employing two rows of elliptical pillars with a 40-µm gap achieves optimal performance. The findings of this investigation underscore the importance of pillars in contactless DEP devices and provide valuable insights for future designs of such microfluidic devices.</p>\u0000 </div>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"46 3-4","pages":"232-239"},"PeriodicalIF":3.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of Withanolides and Withanosides in Ashwagandha Based Products Using HPLC-Drift-Tube-Ion-Mobility Quadrupole Time-of-Flight Mass Spectrometry","authors":"Laura Zellner,&nbsp;Markus Wierer,&nbsp;Markus Himmelsbach,&nbsp;Benjamin Schatzmann,&nbsp;Bernhard Thalhamer,&nbsp;Christian W. Klampfl","doi":"10.1002/elps.202400188","DOIUrl":"10.1002/elps.202400188","url":null,"abstract":"<p>A total of 19 products based on extracts from <i>Withania somnifera</i> (L.) Dunal, better known by its more common name ashwagandha, and five products based on ashwagandha root powder were analyzed with respect to their content in the biologically relevant substances belonging to the group of withanolides and withanosides. Using HPLC coupled to drift-tube ion-mobility quadrupole time-of-flight mass spectrometry (DT-IM-QTOF-MS), 19 withanolides and withanosides could be tentatively identified. The comparison of the results from the quantitative analysis with the information on the product labels showed that the percentage of withanolides and withanosides deviated from the stated specifications by at least a factor of two and at most a factor of 35.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"46 5-6","pages":"340-346"},"PeriodicalIF":3.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/elps.202400188","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143448539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}