ELECTROPHORESIS最新文献

Free solution capillary electrophoresis (CE) has been used to show that non-symmetric, single-stranded DNA oligomers containing 26 nucleotides can exhibit peaks in the electropherograms that correspond to the simultaneous presence of self-dimers and hairpins in the solution. The overlapping hairpin and self-dimer peaks were observed at temperatures close to 15°C in background electrolytes containing at least 80 mM Na⁺ ions. With increasing temperature, the self-dimers were converted first into hairpins and then into random coils at still higher temperatures. The results suggest that hairpins can be an intermediary step in the pathway between DNA duplexes and single-strands.

In pharmaceutical quality control (QC), analytical methods need to maintain release analytics over decades. Over a product's lifecycle, vendors may update instrument hardware and/or software, or a switch between vendors may become necessary upon discontinuation of an instrument. Both situations pose a challenge to pharmaceutical QC.We designed an efficient instrument comparability study to gain a comprehensive understanding of potential performance differences between instruments and therefore rationalize the risk assessment and decision process for a path forward. The results may either point out whether a full or partial re-validation is necessary or whether a science-based update can be pursued based on the data generated in the study. The study design is universally applicable to a substantial range of release analytical methods. In a straightforward setup of two experiments with the new instrument, a statistically meaningful data set is generated for comparison with available historical or validation data of the original instrument. In a Good Manufacturing Practice (GMP) environment, we implemented the study design in a benchmark study comparing the ICE3 and Maurice C imaged capillary isoelectric focusing (icIEF) instruments. The core-study confirmed equal or better performance of the Maurice C in all parameters and serves as a basis for seamless continuation of release icIEF measurements on Maurice C.

Capillary electrophoresis (CE) often offers superior separation relative to chromatography for macromolecules like monoclonal antibodies (mAbs), a major pharmaceutical class. However, electropherogram baselines pose challenges that traditional chromatography algorithms cannot address, requiring complex integration processes. Integration in good manufacturing practice (GMP) laboratories is critically important and has become a focus of data integrity-centric regulatory inspections. Electropherogram integration challenges, the increased use of CE, data systems developed for chromatograms rather than electropherograms, and the increased regulatory scrutiny call for a resolution. This necessity also extends to R&D, clinical, and academic labs. This review examines authoritative sources such as pharmacopoeias, World Health Organization (WHO), Parenteral Drug Association (PDA), and scientific literature. However, none address electropherogram integration. These sources concur that companies should develop integration policies and SOPs. Training programs must ensure analysts are proficient in integration techniques and reviewers are appropriately qualified to assess integrations. Integration parameters must be captured, including slope sensitivity, smoothing factors, and timed events like peak start and stop and baseline correction. Analytical procedures (APs) should include illustrations that define proper integration. Although automatic integration is preferred for its efficiency and objectivity, it is not always accurate. Therefore, manual integration should be permitted under specific conditions, with all settings and iterations documented, justified, and reviewed. Industry collaboration is proposed to create practical integration guidelines specifically for CE.

In the last decade, by integrating experimental and computational analyses, it was demonstrated that halogen bond (HaB) may contribute to binding and enantiorecognition mechanisms underlying the HPLC enantioseparation of halogenated chiral analytes by using cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC)-based chiral columns and n-hexane-based mixtures as mobile phases. When used as a pivotal component of the mobile phase in supercritical fluid chromatography (SFC), carbon dioxide is often considered as an n-hexane-like nonpolar solvent because of its low dielectric constant and zero molecular dipole moment. On the other hand, carbon dioxide may also serve as hydrogen bond (HB) and HaB acceptor due to the presence of nonbonding electrons on the two oxygen atoms, interacting with analyte enantiomers, chiral selectors, and co-solvents. On this basis, we report herein the results of a study aiming at evaluating the impact of using carbon dioxide in SFC in place of n-hexane in HPLC on halogen-dependent enantioseparations by using atropisomeric halogenated 4,4′-bipyridines as analytes and Lux Cellulose-1 as CDMPC-based chiral column. The experimental investigation was complemented by a computational study performed using (a) quantum mechanics (QM) calculations to map and quantify noncovalent interactions possibly underlying the contact of the analytes with carbon dioxide and with the distinctive pendant groups of the CDMPC and (b) molecular dynamics (MD) simulations to visualize noncovalent interactions acting in the analyte 1/CDMPC chromatographic system in different media. The use of MD simulations to model enantioseparations performed in carbon dioxide-based media was not reported in the literature so far.

Withdrawal: Z. Zhu, ‘Quantifying Critical Quality Attributes of Protein Therapeutics by Sodium Dodecyl Sulfate–Capillary Gel Electrophoresis With Native Fluorescence Detection,’ Electrophoresis (Early View): https://doi.org/10.1002/elps.8154.

The above article, published online 30 May 2025 on Wiley Online Library (wileyonlinelibrary.com) has been withdrawn by agreement between the author, Zaifang Zhu, the Editors in Chief Hervé Cottet, Hermann Wätzig, Carlos Garcia, and Wiley-VCH GmbH, Weinheim. The withdrawal has been agreed since the article was published in error before the licence agreement had been signed.

Surface-based biosensor performance is generally limited by mass transfer, especially when detecting low-concentrated species. To address this, dielectrophoresis (DEP) and alternating current electroosmosis (ACEO) can be combined to enhance mass transfer, increasing the target concentration near the sensor. This article presents a method for real-time direct imaging of electrohydrodynamic (EHD) effects on a microparticle suspension within a microfluidic chamber enclosed by two opposing electrodes. This top-bottom configuration was poorly studied in the literature for ACEO. The system presented thereby allows measurements of fluid flow profiles perpendicular to the electrode surface. The velocity of fluorescent latex microsphere tracers was measured as a function of signal frequency, potential, and electrolyte conductivity. This setup enables direct observation of vortices and particle-depleted areas, offering a valuable tool for selecting optimal input parameters—such as electric field, conductivity, and electrode dimensions—to efficiently concentrate microparticles near the sensor. Additionally, a numerical model developed in COMSOL and adapted for this top-bottom configuration enhances understanding of key parameters influencing EHD phenomena.