ELECTROPHORESIS最新文献

Electrokinetic phenomena play a vital role in the study of colloidal nanoparticles, offering significant insights and applications across a wide range of fundamental research and practical uses. It is crucial to recognize the extensive research on various types of nanomaterials, including polymer latexes, quantum dots, and biomolecules. However, there is a significant gap in the study of magnetic systems. Such materials have immense potential and can greatly benefit from both magnetophoretic and electrophoretic techniques. In this work, the electrophoretic behavior of water-based magnetic fluids was investigated, focusing on how additional magnetic field exposure affects their properties. The studies conducted utilized magnetic measurements that emerged from the presence of colloidal particles within the examined systems, which exhibited both charge and magnetic moment. The magnetic susceptibility and magnetization of colloidal particles precipitate formed on one of the electrodes were measured. The thickness of the formed precipitate on the electrode can be confidently estimated through micrometric measurements as well as by analyzing its magnetic susceptibility during electrophoresis. A formula for calculating the electrophoretic velocity based on the results of magnetic measurements was obtained. Estimates of zeta potential and charge of colloidal particles were carried out. The electrophoresis process in these systems can be effectively regulated by an inhomogeneous magnetic field, leading to complete compensation.

Current Y-chromosomal single-nucleotide polymorphism (Y-SNP) detection technologies in forensic genetics often rely on bulky equipment, complex procedures, and lack adaptability to field conditions. To address these limitations, we developed an 89-plex microfluidic Y-SNP system comprising a disposable DNA extraction/amplification chip and a capillary electrophoresis chip. Using in situ lyophilization, the reagents are stabilized for long-term storage. Integrated with a portable device, the system enables a fully automated “sample-in-answer-out” workflow and delivers complete 89-locus Y-SNP genotyping within 139 min. The system includes two panels—AIYSNP42 for global high-frequency haplogroups and AIYSNP47 for East Asian O-haplogroup subclades—designed on the basis of the International Society of Genetic Genealogy (ISOGG) phylogenetic tree for multi-level resolution. Validation showed a detection sensitivity of 2.5 ng of DNA, with a 93.6% genotyping success rate across 94 forensic samples. It maintained performance under environmental inhibitors (humic acid ≤ 100 ng/µL, hemin ≤ 300 µM, indigo ≤ 15 mM) and moderate UV-induced DNA degradation. The system demonstrated excellent reproducibility (coefficient of variation, CV < 0.5%) and reliably detected male DNA in mixtures (≥2% in male–female, ≥33% in male–male). This microfluidic system reduces the reliance on the need for conventional laboratory workflows and supports rapid, on-site Y-SNP analysis for pedigree tracing, ancestry inference, and mixture interpretation.

A novel DC-dielectrophoresis (DEP) method employing a tunable insulating microdroplet for the continuous sorting of microtargets is presented in this article. To induce the dielectrophoretic effect, a DC electric voltage is applied via the microdroplet through the microchannel to induce the gradient of the inhomogeneous electric field. When passing through the gap between the microdroplet and the channel where there is the strongest nonuniformity of the electric field, the microparticles experience the DEP effects, and their trajectories shift. The effects of the gap spacing and the applied voltage on the distribution of the electric field gradient and the effect of the flow rate on the particle trajectory were analyzed numerically. On the basis of theoretical analysis, a tunable microdroplet-based microfluidic chip was fabricated, and the experimental system platform centered on the tunable droplet chip was constructed. Experiments were conducted to demonstrate the sorting of 5 and 10 µm polystyrene microparticles by adjusting the joint gap distance, flow rate, and applied voltage. The experimental results were in good agreement with the numerical simulation, which proved the feasibility of using microdroplet to serve as tunable insulator for the manipulation and separation of microtargets.

In this study, ion chromatography (IC) methods were developed and validated for the determination of sodium, potassium, phosphate, and sorbitol in phosphate syrup. For the analysis of cations, an IonPac CS16 column was utilized, with a mobile phase of 50 mM methanesulfonic acid and a flow rate of 0.5 mL/min. For the analysis of phosphate and sorbitol, an IonPac AS19 column was employed, using a flow rate of 1.0 mL/min and mobile phases of 50 and 20 mM NaOH, respectively. In the validation tests, sensitivity was assessed on the basis of the signal-to-noise ratio, with the limit of detection for all analytes being below 0.001 mM. The linearity curves for all analytes exhibited determination coefficients greater than 0.999, indicating excellent linearity. The relative standard deviation (RSD%) for both inter-day and intra-day precision was not more than 1%. Accuracy, expressed as recovery (%), ranged from 98% to 101% for all ions. The validation of these methods demonstrated their reliability for the measurement of these four analytes. Furthermore, the stability of the syrup was evaluated over 6 months at room temperature (25°C). The results indicated that the phosphate syrup remained stable under these conditions, with the analyte contents staying close to 100%.

Siponimod fumarate (SIP), a potent selective S1P receptor modulator, has emerged as a critical therapeutic agent in the treatment of multiple sclerosis. Recognizing the increasing regulatory demands for robust impurity profiling and method reliability, this study reports the development and optimization of an HPLC method for the simultaneous determination of SIP and its related impurities in both bulk drug substance and tablet dosage forms. The method was developed within an Analytical Quality by Design (AQbD) framework, guided by ICH Q14 principles, ensuring a systematic and risk-based approach throughout the analytical lifecycle. Chromatographic separation necessary for resolving critical impurities was achieved on an XSelect HSS T3 column (150 mm × 4.6 mm, 3.5 µm) using a stepped gradient elution program with 0.1% perchloric acid in water and acetonitrile as the mobile phases. Optimal separation conditions, identified through the AQbD process to meet stringent performance criteria, were determined at a column temperature of 42.5°C, a flow rate of 1.4 mL min⁻¹, and UV detection at 212 nm. The method performance was rigorously evaluated through accuracy profiles, confirming both its precision and trueness across the targeted concentration range. In parallel, as part of a holistic method characterization, environmental sustainability was assessed using comprehensive greenness metrics, whereas its practical applicability was further substantiated using the Blue Applicability Grade Index (BAGI) and the Red–Green–Blue 12 (RGB12) algorithms. This approach not only bridges the gap created by the absence of an official pharmacopoeial monograph for SIP but also offers a robust, well-characterized, and sustainable platform for pharmaceutical quality control, aligning method development with both regulatory performance needs and environmental awareness.