ELECTROPHORESIS最新文献

Foodborne pathogenic bacteria always threaten human health. Flavonoids are commonly used in antibacterial applications. Studying the antibacterial effect of flavonoids on bacteria is significant. Capillary electrophoresis is a versatile separation means. It has different separation modes, so, it can be applied in the analysis of both bacteria and flavonoids. In this study, an efficient method of indirect separation and detection of three bacteria Vibrio parahaemolyticus, Escherichia coli, and Staphylococcus aureus was developed. The determination of bacteria was realized by separating the aptamers corresponding to the bacteria by capillary sieving electrophoresis. This method avoided the disadvantages of low resolution, channel adsorption and bacterial aggregation, encountered in the direct separation of bacteria. The separation of the flavonoid kaempferide was realized by capillary zone electrophoresis, and kaempferide in Kaempferia galanga was determined. Kaempferide and the extract of Kaempferia galanga were applied in the antibacterial tests separately. Using the developed method, the bacterial growth curves and the curves of the kaempferide concentration were studied respectively. The results showed that both kaempferide and Kaempferia galanga could effectively inhibit the bacteria. The inhibitory effect on the terrestrial bacteria Escherichia coli, and Staphylococcus aureus was better than that on the marine bacterium Vibrio parahaemolyticus.

While traditional dielectrophoretic methods for nanoparticle enrichment and filtration are versatile and selective, they struggle to handle higher throughput applications. To address this challenge and enhance the practical application of dielectrophoresis, we propose an innovative design for porous sandwiched nanofiber electrodes. The electrode is fabricated through a simple process involving the electrospinning of nanofibers with a diameter of 216 ± 28 nm and mat thickness of around 70 µm, followed by the deposition of a thin chromium/gold layer (approximately 140 nm thick) on both sides. This process ensures no electrical short circuit occurs between the electrodes, and it maintains a sheet resistance of 7.19 Ω/□. The resulting significant electric field gradients are capable of trapping nanoparticles with diameters of 100 nm and 40 nm. The structure's sub-micrometer features and large active surface area allow for trapping of nanoparticles at a flow rate of 3.6 mL/h. To evaluate the effects of applied voltage and volumetric flow rate, we conducted experiments with constant voltage while varying the flow rate and constant flow rate while varying the voltage. Our findings indicate that trapping performance improves with higher AC voltage but decreases at higher flow rates. These insights are crucial for optimizing parameters for large-scale nanoparticle enrichment and filtration. This proof-of-concept study for flow through dielectrophoresis of nanoparticles paves the way for a device suitable for large-scale sample processing and higher throughput/separation efficiency in practical settings.

Tumor–macrophage interactions play a key role in various physiological and pathological processes, such as angiogenesis, immune suppression, and extracellular matrix remodeling. In this study, a biomimetic microfluidic chip was developed to simulate the immune microenvironment of glioma through the co-culture of glioma cells and macrophages in a three-dimensional (3D) matrix. Glioma cells were embedded in collagen I solution after forming spheroids in the microwell array chip and subsequently co-cultured with macrophages in different channels. This chip enabled the real-time monitoring of morphological changes in macrophages, the invasion of glioma cell spheroids, and molecular interactions between different cell types. Two distinct cell types could be extracted and isolated in situ for subsequent molecular biological detection, such as Western blotting or qPCR. The results demonstrated that glioma cell spheroids significantly enhanced invasiveness in the presence of macrophages. Moreover, the phenotype of macrophages altered from M0 to M2 (tumor-supportive) under the influence of tumor cells. The molecular mechanism mediating this reciprocal process was extensively explored. It is believed that this 3D microfluidic tumor model could serve as a useful tool for studying the biological properties of the glioma microenvironment. In addition, a more comprehensive understanding of the mechanisms involved in glioma metastasis could be obtained, especially of how tumor inflammatory cells, including tumor-associated macrophages (TAM), affect invasion process.

Nowadays, Y chromosome short tandem repeats (Y-STRs) are widely used in forensic medicine practice, which has great significance for ancestry tracing, male lineage evolution, and male paternal relatives. Rapidly mutating Y-STRs (RM Y-STRs) have been shown to have greater potential to distinguish males from males in the patrilineal line. Therefore, a novel 5-dye fluorescent multiplex system with 30 Y-STRs was developed and optimized to screen out more RM Y-STRs and fasting mutating Y-STRs (FM Y-STRs). New primers were designed, and composite system construction was carried out. A series of experiments were conducted following the guidelines of the Scientific Working Group on DNA Analysis Methods (SWGDAM), including polymerase chain reaction (PCR) amplification conditions, sensitivity, stability, species specificity, mixture and degraded sample studies, mutation analysis, and population studies. The results suggested that changing PCR amplification conditions in a reasonable range hardly affected the genotyping. The system showed excellent sensitivity and stability in sensitivity and stability studies. Even with UV-C exposure for up to 96 h, the system performed well in male blood samples and semen–vaginal secretion mixtures. Mutation analysis was performed on 582 father–son pairs, and 4 RM Y-STRs and 7 FM Y-STRs were identified, with mutation rates ranging from 1.72 × 10⁻³ to 20.62 × 10⁻³. Furthermore, on the basis of mutation rate analysis, eight machine learning methods were used to construct and compare patrilineal relationship prediction models, inferring the relationship by predicting the number of meiosis. Overall, the multiplex system displays favorable performance and has a greater potential for application in forensic science practice.

Skeletal remains, often partially or completely decomposed, are among the most common biological forensic samples found at crime scenes. Analyzing these incomplete specimens to estimate the age of the deceased is crucial. Previous studies on DNA methylation-based age prediction in bones have not evaluated differences across skeletal elements or clarified how bone type influences prediction accuracy. This study focuses on postmortem rib samples—a common forensic specimen—to develop a DNA methylation-based age prediction model specific to ribs. DNA methylation levels at eight CpG sites within the ELOVL2, FHL2, KLF14, and FAM123C genes were analyzed using pyrosequencing in 81 postmortem rib samples and 112 postmortem blood samples, with 50 individuals providing both sample types simultaneously. The rib-derived age prediction model exhibited an R² value of 0.908, whereas the blood model achieved an R² value of 0.927. For the rib model, the mean absolute deviation (MAD) of the training set was 4.813 years, and the MAD of the testing set was 5.084 years. The blood model showed slightly higher accuracy in predicting the age of the same individuals. Notably, cross-tissue application of models led to significant prediction bias, emphasizing the necessity of tissue-specific calibration for methylation-based age estimation. Exploratory analysis of postmortem sternum, rib, and frontal bone samples from 12 individuals revealed no statistically significant differences in methylation levels or age estimates across bone types. However, broader generalizability of the rib model to these skeletal elements requires validation in larger, independent cohorts. This work establishes a robust age prediction framework for rib samples, highlights the critical role of tissue specificity in epigenetic forensic models, and provides preliminary evidence for potential cross-bone applicability.

Understanding protein–excipient interactions is vital for biopharmaceutical formulation, as they influence stability and pharmacokinetics (PK). Cyclodextrins (CDs) are widely used excipients that enhance solubility and stability, but their weak interactions with polypeptides remain poorly characterized. Relaxin (RLX), a potent anti-heart failure polypeptide, was selected due to its PK relevance and in vivo interaction with human serum albumin (HSA). Given RLX's poor solubility, CDs were identified as the most effective solubilizers. However, traditional affinity assays lack the sensitivity to detect weak CD-polypeptide interactions. To overcome this limitation, we employed affinity capillary electrophoresis and flow-induced dispersion analysis (FIDA) to assess RLX's binding with hydroxypropyl-β-cyclodextrin (HP-β-CD) and sulfobutylether-β-cyclodextrin (SBE-β-CD). Our results showed a higher affinity for SBE-β-CD than HP-β-CD, though both interactions were significantly weaker than RLX's binding to HSA. These findings provide key insights into weak CD-polypeptide interactions, supporting SBE-β-CD as an excipient to improve solubility without compromising PK performance. Additionally, the effectiveness of these rapid, nonconventional analytical methods was validated through in vivo PK studies in a cynomolgus monkey model, highlighting their value in excipient–protein binding research.