ELECTROPHORESIS最新文献

Brucellosis is a neglected zoonotic disease that continues to impact global public health and livestock economies, particularly in regions with limited diagnostic infrastructure. Its causative agent, Brucella abortus, is difficult to detect due to its intracellular lifestyle and the nonspecific symptoms it causes in humans. This study demonstrates the experimental application of dielectrophoresis (DEP) in a microfluidic device for the selective manipulation of polystyrene beads and inactivated B. abortus bacteria. By tuning the frequency and medium conductivity, reliable combined negative dielectrophoretic (nDEP) and hydrodynamic flow responses were achieved, leading to the deflection of bacterial cells across the microchannel within a critical vertical window for particle control. Distinct particle trajectories were observed under varying electric field conditions, confirming effective separation without the need for labels or biochemical markers, except for visual validation. This label-free strategy enables rapid sample processing and has the potential to be integrated into portable platforms for on-site diagnostics. The results highlight the feasibility of DEP-based approaches for pathogen separation and support their future implementation in brucellosis surveillance and point-of-care testing.

CRISPR-Cas9-targeted sequencing can enrich DNA regions of interest by directing the Cas9 protein to bind and cleave specific DNA sequences via single-guide RNA (sgRNA). It is interesting to explore the efficacy of using CRISPR-Cas9-targeted nanopore sequencing (referred to as Cas9-seq), a polymerase chain reaction (PCR)-free workflow, for forensic short tandem repeats (STR) profiling, and to compare it with the amplification-based approach. In this pilot study, we constructed a Cas9-seq method for profiling seven STR loci, including D18S51, FGA, TPOX, D16S539, vWA, CSF1PO, and TH01. With 3 µg DNA inputs from human NA12878 and 293T cell lines, we achieved 643.45- and 468.34-fold enrichment ratios of the sgRNA-targeted regions by using Cas9-seq, respectively. Compared to nanopore sequencing of PCR amplicon products (amplicon-seq) of the ForenSeq DNA Signature Prep kit, the Cas9-seq reads had an ultralow strand bias. However, surprisingly, Cas9-seq did not show advantages in allele balance and had higher noise in the reads. At the seven STR loci for the two samples, both Cas9-seq and amplicon-seq had three genotyping errors. Additionally, there were no false-positive single-nucleotide polymorphisms (SNPs) introduced by Cas9-seq, whereas amplicon-seq produced three. In sum, we conclude that the PCR-free Cas9-seq might not be favorable for forensic STR genotyping.

This study investigates dynamic electrohydrodynamic (EHD) interactions between two identical colloidal microspheres in rotating electric fields using a fully coupled three-dimensional transient model. Long-range dielectrophoretic (DEP) attraction drives radial convergence; upon near-contact, tangential EHD sliding further induces asynchronous co-field orbital revolution. Crucially, individual electrorotation (ER) not only retains its original direction but also maintains a stable rate—with the rate deviating by <5% from that of isolated particles, matching single-particle behavior. High-frequency DEP force polarity reversal establishes stable noncontact equilibria via short-range repulsion. Spectral analyses reveal collective dynamics (radial mobility, orbital motion) stem from rotating electric field-mediated gap modulation rather than altered particle polarization. This dynamic decoupling—governed by the Kramers–Kronig relationship between real (radial DEP) and imaginary (rotational ER) components of polarizability—enables independent positional and rotational control, opening new avenues for noncontact colloidal manipulation in microfluidic mixers and dynamically reconfigurable active matter systems, where conventional DEP-based approaches are limited by coupled dynamics.

High-performance capillary electrophoresis (CE) has been widely applied in the analysis of organic acids, especially monocarboxylic acids (MAs), but no studies on the CE analysis of dissociated states of MAs have been reported. Here, 15 MAs were analyzed by the newly developed universal interface-induced current detector (IICRD). Two current signal peaks were observed in current electrophoretograms (CR-EGs), whereas only one peak with low sensitivity can be obtained by diode array detector (DAD). The current signal peaks of MAs were accurately identified by adding a charge-neutral marker and calculating by pK_a. The qualitative analysis indicated that the two current signal peaks of MAs were charge-neutral forms [MA^±] and monovalent anions [MA⁻] in order. Quantitative analysis showed that CE-IICRD can enhance the sensitivity of MA analytes to 40 µM in limit of detection (LOD), with a linear range from 10⁻⁶ to 10⁻² M. Furthermore, interactions between different dissociated states of MAs and monocarboxylate transporter 1 (MCT1) were studied by combined application of nonimmobilized cell CE (NICCE) method for the first time. The binding kinetic parameters and mole number of MCT1 on cell membranes can also be obtained. Besides, competitive binding experiments proved that BAY-8002 (MCT1-specific inhibitor) and lactic acid shared the same binding site. CE-IICRD provides a new method to reveal the interaction between different dissociated forms of MAs or other biomolecules and essential receptors.