ELECTROPHORESIS最新文献

{"title":"A Low-Cost Microfluidic Device For the On-Line Counting of Microparticle/Bacteria","authors":"Zhen-Yu Xun,&nbsp;Lv Liu,&nbsp;Bai-Chuan Zhang,&nbsp;Liang-Liang Fan,&nbsp;Lu-Wei Zhang,&nbsp;Hong Zhao,&nbsp;Sohail Iqbal,&nbsp;Rana Iqtidar Shakoor,&nbsp;Liang Zhao","doi":"10.1002/elps.202400061","DOIUrl":"10.1002/elps.202400061","url":null,"abstract":"<div>\u0000 \u0000 <p>On-line counting of the microparticle/bacteria in the liquid medium has great potential in the food safety and biomedical fields. A new low-cost microfluidic device is proposed for the on-line counting of the microparticles/bacteria in the liquid medium. The gradually contracted microchannel and the viscoelastic fluid are combined to achieve the efficient elastic focusing of the particle/bacteria, which significantly improves the counting accuracy by aligning all particles/bacteria in a single position at the center of the microchannel. A simple light resistance-based counting method is designed and integrated with the microchannel, where the low-cost elements including the laser pointer, convex lens, diaphragm, and photodiode, are used to build the optical path of detection. The influence of the flow rate, the particle size, the property of fluid, and the channel structure on the focusing of the particle/bacteria are investigated by the experiment, and the counting ability of the integrated microfluidic device is validated by using different-sized microparticles and the <i>bifidobacterium</i>. With its simple structure, low cost, easy operation, and high efficiency, this microfluidic device is suitable for the commercial applications, such as the on-line counting of the plastic microparticle in water or the colony-forming units (CFU) of bacteria in food.</p>\u0000 </div>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"45 23-24","pages":"2182-2190"},"PeriodicalIF":3.0,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142767232","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":"Electromigration of Charged Analytes Through Immiscible Fluids in Multiphasic Electrophoresis","authors":"Md Nazibul Islam,&nbsp;Yang Liu,&nbsp;Amy E. Herr","doi":"10.1002/elps.202400192","DOIUrl":"10.1002/elps.202400192","url":null,"abstract":"<p>Multiphasic buffer systems have been of greatest interest in electrophoresis and liquid–liquid electrotransfer; this study extends that foundation by exploring the interplay of the geometric and viscous properties of an interleaving oil layer on the electrotransfer of a charged analyte from an aqueous solution into a hydrogel. We utilized finite element analysis to examine two complementary configurations: one being electrotransfer of a charged analyte (protein) in an aqueous phase into a surrounding hydrogel layer and another being electrotransfer of the protein from that originating aqueous phase—through an interleaving oil layer of predetermined viscosity and thickness—and into a surrounding hydrogel layer. Results indicate that the presence of an oil layer leads to increased skew of the injected peak. To explain this difference in injection dispersion, we utilize Probstein's framework and compare the Péclet (<i>Pe</i>) number with the ratio between length scales characteristic to the axial and radial dispersion, respectively. The formulation assigns electrotransfer conditions into six different dispersion regimes. We show that the presence or absence of an interleaving oil layer moves the observed peak dispersion into distinct electrotransfer regimes; the presence of an oil layer augments the electrophoretic mobility mismatch among the different phases, resulting in a five-fold increase in <i>Pe</i> and a six-fold increase in the ratio between the axial to radial dispersion characteristic lengths. We further show that oil viscosity significantly influences resultant injection dispersion. A decrease in oil-layer viscosity from 0.08 to 0.02 Pa s results in a &gt;100% decrease in injection dispersion. Our theoretical predictions were experimentally validated by comparing the electrotransfer regimes of three different mineral oil samples. We show that lowering the oil viscosity to 0.0039 Pa s results in an injection regime similar to that of the absence of an oil layer. Understanding of the impact of electrotransfer of charged species across multiple immiscible fluid layers on peak dispersion informs the design of multiphasic electrophoresis systems.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"46 1-2","pages":"13-21"},"PeriodicalIF":3.0,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11773303/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142767247","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":"Determination of the Effective Charge Numbers and Ionic Mobilities of Single Isomer and Randomly Highly Sulfated Cyclodextrins by Capillary Isotachophoresis and Zone Electrophoresis.","authors":"Veronika Šolínová, Dušan Koval, Václav Kašička","doi":"10.1002/elps.202400207","DOIUrl":"https://doi.org/10.1002/elps.202400207","url":null,"abstract":"<p><p>Sulfated cyclodextrins (CDs) are multiply negatively charged molecules widely used as chiral selectors in capillary electrophoresis (CE). In some of their applications, the effective charge numbers of their molecules were observed to be lower than the numbers of the attached sulfated groups due to strong binding of counterions. However, degree of reduction of the theoretical charge was not quantified. For that reason, in this study, capillary isotachophoresis (CITP) and capillary zone electrophoresis (CZE) were applied for the determination of the effective charge numbers and actual ionic mobilities of two kinds of sulfated CDs: single isomer sulfated α-, β-, and γ-CDs (SI-CDs) and randomly highly sulfated α-, β-, and γ-CDs (HS-CDs). The effective charge numbers of the SI-CDs and HS-CDs were determined from the length of their ITP zones, the ionic mobilities determined by CZE, and molar concentrations of their solutions applied for CITP analysis, and from the same parameters of reference compounds, formic acid for SI-CDs and dichloroacetic acid for HS-CDs. The determined effective charge numbers of the SI-CDs were equal to or only slightly lower than the numbers of sulfate groups in their molecules but the effective charge numbers of randomly HS-CDs were significantly (22.2%-27.8%) reduced as compared to the average numbers of sulfate groups in their molecules. In accordance with a lower number of sulfate groups in SI-CDs than in HS-CDs, the absolute values of the actual ionic mobilities of SI-CDs (35.5-37.5) × 10^-9 m² V^-1 s^-1 were lower than those of HS-CDs (43.5-44.1) × 10^-9 m² V^-1 s^-1.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738718","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":"Enhancing Doxorubicin Detection: Multiphase Electroextraction for Efficient and Affordable UHPLC-DAD Analysis in Saliva.","authors":"Denise V M Sousa, Fabiano V Pereira, Ricardo M Orlando","doi":"10.1002/elps.202400094","DOIUrl":"https://doi.org/10.1002/elps.202400094","url":null,"abstract":"<p><p>Attesting optimal drug concentrations in biological fluids is crucial to ensure precise dosage adjustment, to guarantee therapy adherence, and to manage side effects in chemotherapy. Accurate drug determination relies on liquid chromatography and advanced detectors, with sample preparation playing a pivotal role, especially in complex matrices such as biological fluids. This study introduces a multiphase electroextraction (MPEE) of doxorubicin (DOX) in saliva by utilizing a paper point, followed by ultra-high-performance liquid chromatography coupled to diode array detection. The extraction time and electric potential were carried out by using the Doehlert optimization approach, whereas the desorption solvent was fine-tuned through the centroid-simplex experimental design. After optimization, DOX and the internal standard were extracted in 35 min, utilizing an applied voltage of 300 V and a multiwell plate capable of simultaneous extraction of 66 samples. The recovery was 87%-101%, with a linear range between 50 and 500 µg L^-1 (R² > 0.999). The intra- and inter-assay coefficients of variation for precision were <10%, and the limit of detection and limit of quantification were 25 and 50 µg L^-¹, respectively. When applied to five different fortified saliva samples, there were no statistically significant differences in the detected concentrations. Although the enrichment factor (0.6) was not as high as expected, the other results confirm that the method obtained is suitable for monitoring DOX in this complex matrix and can contribute to further developments in sample preparation using MPEE approaches.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738719","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":"When to Use Rectangular Waveforms in Dielectrophoresis Application to Increase Separation and Sorting Efficiency","authors":"Niklas P. Boldt,&nbsp;Laura Weirauch,&nbsp;Jana M. Späth,&nbsp;Uwe Kerst,&nbsp;Mario Birkholz,&nbsp;Michael Baune,&nbsp;Roland Thewes","doi":"10.1002/elps.202400164","DOIUrl":"10.1002/elps.202400164","url":null,"abstract":"<p>In this study, the influence of using rectangular waveforms is comprehensively investigated on the separation and sorting efficiency of dielectrophoretic (DEP) processes. Besides positive effects on DEP experiments, cases of a diminished force due to rectangular waveforms are investigated and discussed. This investigation encompasses two primary experimental setups. First, microparticle-focusing experiments are carried out using a pair of electrodes within a microfluidic channel. Second, separation experiments are performed using a macroscopic insulator-based dielectrophoretic filter. The study reveals that harmonics of rectangular signals can have a positive impact on separation or sorting efficiency when compared to sinusoidal waveforms, provided that these harmonics contribute to the overall DEP force with the same sign. This positive effect is found to depend on the ratio between the applied fundamental frequency and the cross-over frequency in the Clausius–Mossotti factor. However, violating related derived boundary conditions leads to negative effects and a decrease in the DEP net force.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":"46 1-2","pages":"104-111"},"PeriodicalIF":3.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11773296/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738725","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":"Short Communication: Ultralow Voltage Electrokinetic Particle Trapping in DC-iEK Devices Using 9 V Alkaline Batteries as Power Supply.","authors":"J Martin de Los Santos-Ramirez, Vania G Martinez-Gonzalez, Carlos A Mendiola-Escobedo, Jose M Cotera-Sarabia, Roberto C Gallo-Villanueva, Rodrigo Martinez-Duarte, Victor H Perez-Gonzalez","doi":"10.1002/elps.202400141","DOIUrl":"https://doi.org/10.1002/elps.202400141","url":null,"abstract":"<p><p>This contribution describes direct current insulator-based electrokinetic (DC-iEK) microfluidic devices stimulated by 9 V alkaline batteries for the trapping of 2-µm diameter fluorescent polystyrene particles. These devices featured two triangular insulating posts within the fluidic channel. Particle trapping was clearly observed at 18 V (two 9 V batteries connected in series), but only intermittent particle trapping was observed with a single 9 V battery. Particle trapping was determined by measuring the increase in relative fluorescence intensity at the gap region between the single pair of triangular posts. Results demonstrate that the use of low stimulating voltages (deemed as ultralow) in DC-iEK systems may be more suitable for accurate and precise electrokinetic characterization of particles-by exhibiting a very well-localized trapping region with negligible particle oscillations therein, respectively-than for high-performance and high-throughput particle manipulation (i.e., concentration, separation, filtering, or isolation).</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738722","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":"Optical Determination of the Internal Capillary Diameter Used in Taylor Dispersion Analysis.","authors":"Sébastien Roca, Laurent Leclercq, Philippe Gonzalez, Chutintorn Somnin, Marta Garrido Alvarez, Laura Dhellemmes, Joseph Chamieh, Hervé Cottet","doi":"10.1002/elps.202400156","DOIUrl":"https://doi.org/10.1002/elps.202400156","url":null,"abstract":"<p><p>In this work, we describe an optical setup to determine the internal diameter of narrow bore fused silica capillary used in capillary electrophoresis and Taylor dispersion analysis (TDA). Indeed, fluctuations up to about ±3-4 µm on the capillary I.D. can generate important inaccuracy on the hydrodynamic radius determination by TDA. Calibration of the optical set-up, impact of the operator and of the placement of the capillary in the focal plane, and the influence of the way to cut the capillary were investigated and discussed. This optical set-up was next used to determine capillary I.D. on a 60 m long capillary spool. Relatively small variations were observed along a 60 m capillary spool (0.3 µm maximum variation), while important I.D. fluctuations can be observed from capillary batch to batch. Taking three capillaries of three different nominal I.D. values, R_h values of sodium benzoate obtained by TDA were not significantly different if the capillary I.D. were optically measured, while significant variations were observed with the nominal I.D. values. A protocol based on TDA of sodium benzoate was proposed for calibrating narrow bore fused silica capillary I.D. without the use of optical measurements for researchers that would not have access to such optical equipment.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142749649","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":"Contactless Conductivity Detection for Capillary Electrophoresis-Developments From 2020 to 2024.","authors":"Peter C Hauser, Pavel Kubáň","doi":"10.1002/elps.202400217","DOIUrl":"https://doi.org/10.1002/elps.202400217","url":null,"abstract":"<p><p>The review covering the development of capillary electrophoresis with capacitively coupled contactless conductivity detection from 2020 to 2024 is the latest in a series going back to 2004. The article considers applications employing conventional capillaries and planar lab-on-chip devices as well as fundamental and technical developments of the detector and complete electrophoresis instrumentation.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738716","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":"Flow Rate Determination of the Nanoflow Sheath Liquid CE-MS-Coupling Applying the nanoCEasy Interface.","authors":"Alisa Höchsmann, Jasmin Schairer, Oliver Schott, Ralf Höneise, Christian Neusüß","doi":"10.1002/elps.202400191","DOIUrl":"https://doi.org/10.1002/elps.202400191","url":null,"abstract":"<p><p>In recent years, nanoflow sheath liquid (nanoSL) interfaces have been used more commonly for capillary electrophoresis-mass spectrometry (CE-MS) coupling due to their high sensitivity combined with flexibility in CE separation conditions. So far, the exact amount of sheath liquid (SL) and, thus, the dilution effect remain unknown due to the self-supplying type of the nanoSL interfaces. To quantify the SL flow rates, we present here an approach for the determination of the flow rate based on isotopically labeled standards using the nanoCEasy interface. SL and pumped CE flow are spiked with atrazine and d5-atrazine, respectively, enabling the determination of the total flow rate for different electrospray (ES) conditions. Generally, flow rates increase with higher ES voltages. Only at high ES voltages, larger emitter sizes lead to higher flow rates; for low voltages, flow rates are independent of emitter size. Additionally, smaller emitter sizes can generally be operated at lower ES voltages. Visualizing the ES, higher flow rates lead to a larger spray angle. Higher flow rates may decrease the signal intensity by diluting the CE-separated analytes. Indeed, this effect is observed for the flow-injected atrazine analytes and in the CE-MS analysis of an amino acid standard mix under aqueous acidic separation conditions. Therefore, lower flow rates are preferred for low electroosmotic flow (EOF) applications. However, in high EOF applications, higher voltages are required to prevent the accumulation of aqueous background electrolyte (BGE) at the emitter tip, which otherwise leads to peak broadening and inefficient ionization. Overall, the presented data enable the selection of stable and sensitive settings for nanoSL interfaces.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142738721","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 Green Fluorescent Protein Streaming Dielectrophoresis in Insulator-Based Microfluidic Devices.","authors":"Jerry Sheu, Sean Seyler, A K M Fazlul Karim Rasel, Mark A Hayes","doi":"10.1002/elps.202400123","DOIUrl":"https://doi.org/10.1002/elps.202400123","url":null,"abstract":"<p><p>There is tantalizing evidence that proteins can be accurately and selectively manipulated by higher order electric field effects within microfluidic devices. The accurate and precise manipulation of proteins in these platforms promises to disrupt and revolutionize many fields, most notably analytical biochemistry. Several lines of experimental evidence suggest much higher forces are generated compared to those calculated from traditional theories and those higher forces arise from subtle structural features of the proteins providing selectivity. New theories reflect some of the experimental evidence in the magnitude of the force predicted and inclusion of subtle structural features absent in traditional continuum theory. Unfortunately, the experimental evidence is largely exploratory in nature and lacks one or more important elements that prevents a clear interpretation and comparison to not only the other existing data, but also quantitative comparison to the evolving theoretical descriptions. Here, a clear and interpretable experimental system is presented that quantitatively determines the dielectrophoretic susceptibility of unlabeled, unaggregated native-structure protein molecules that are exposed to modest electric fields (10⁵-10⁶ V/m) for short periods of time (∼5 ms) without significant increases in local concentration. The platform uses sub-nanogram quantities of protein, the probed volume upon determination is a few picoliters, and the total analysis time is 10 s.</p>","PeriodicalId":11596,"journal":{"name":"ELECTROPHORESIS","volume":" ","pages":""},"PeriodicalIF":3.0,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142616791","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}