Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Conference Object Investigation of a Magnetic Levitation Density Measurement System(Institute of Electrical and Electronics Engineers Inc., 2025) Gümüş, S.; Öztürk, Y.Magnetic levitation systems are widely used for density measurements in biomedical research and sensor technologies. These systems consist of pairs of magnets with like poles facing each other, creating a repulsive magnetic field. Levitation occurs as diamagnetic particles are suspended in a paramagnetic fluid between the magnets. The force acting on the particles is proportional to the product of the magnetic field and its gradient, while the concentration of the paramagnetic fluid influences the magnitude of the force. To optimize sensor performance, both magnetic field strength and paramagnetic ion concentration must be considered. In this study, two magnets in an anti-Helmholtz configuration (62 × 3 × 12 mm) were used, with a variable gap distance (g). Experimental analysis was conducted to investigate the effect of magnetic field strength and fluid concentration on levitation behavior. Initially, g was set to 1.8 mm, and Gadolinium-based paramagnetic fluid (Gadovist) was prepared at 30 mM, 45 mM, and 60 mM concentrations. Microplastic particles with densities of 1.05 g/cc and 1.09 g/cc were added into the solutions. Levitation heights, measured relative to the bottom magnet, increased with concentration: 0.60-0.51 mm and 0.43-0.39 mm at 30 mM; 0.70-0.66 mm and 0.49-0.47 mm at 45 mM; and 0.76-0.71 mm and 0.63-0.61 mm at 60 mM for 1.05 g/cc and 1.09 g/cc particles, respectively. In the second stage, g was increased to 2.4 mm and 3 mm using 60 mM fluid. Levitation heights were 0.69-0.68 mm and 0.55-0.49 mm at 2.4 mm; and 0.65-0.64 mm and 0.48-0.47 mm at 3 mm, respectively. These results were compared with theoretical calculations, and sensor performance was evaluated for different application scenarios, contributing to the development of future levitation-based sensing systems. © 2025 IEEE.Article Magnetic Levitation-Based Determination of Single-Nuclei Density(Elsevier, 2026) Anil-Inevi, Muge; Sarigil, Oyku; Unal, Yagmur Ceren; Tekin, H. Cumhur; Mese, Gulistan; Ozcivici, EnginThe biophysical properties of cells and intracellular compartments provide critical insights into their structural and functional states, holding significant potential for biological and medical applications. Single-cell density has recently emerged as a promising biomarker in various research areas, including disease detection, making its precise measurement in biological samples an important analytical objective. Magnetic levitation offers significant advantages over traditional density detection techniques by enabling single-cell analysis rather than bulk measurements, providing precise quantification while preserving natural sample properties and eliminating the need for complex and expensive equipment. While magnetic levitation has been successfully applied to singlecell and cell-aggregate analysis, its use for subcellular compartments remains unexplored. Here, we demonstrate the first application of magnetic levitation technology for the density-based analysis of cell nuclei, a critical organelle essential for genomic preservation and organization. To accommodate the unique size and density characteristics of nuclei compared to whole cells, we systematically investigated appropriate paramagnetic agents, sample loading concentrations, and nuclear equilibrium times required for optimal levitation. We mapped density distributions of nuclei from different cell lines and conducted parallel assessments of cellular and nuclear density changes following cell cycle perturbations and treatments inducing cell death through distinct mechanisms. Our findings establish magnetic levitation as a powerful tool for subcellular density analysis, with potential applications in cell biology research and clinical diagnostics through improved understanding of subcellular physical parameters.Conference Object Magnetic Levitation-Based Viscosity Measurement in a Microcappilary Channel(Chemical and Biological Microsystems Society, 2022) Doyran, O.; Tekin, H.C.Viscosity, has been known as the key rheological parameter, to characterize biological, chemical and physical material properties. In this work, we have developed a magnetic levitation-based viscosity measurement method in a microcapillary channel. For this purpose, polymer microspheres are utilized as microsensors to correlate solution viscosity to microspheres' velocity while microspheres are balanced at a stable levitation position. This inexpensive and practical system enables rapid viscosity measurement from low amount of sample. © 2022 MicroTAS 2022 - 26th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.Conference Object Citation - WoS: 1Citation - Scopus: 5Otomatik Dijital İmge Analizi Kullanılarak Manyetik Levitasyon Platformunda Mikroparçaçıkların Özkütlelerinin Belirlenmesi(IEEE, 2018) Tekin, H. CumhurIn this study, a program, which will allow an automatic determination of density data by performing digital image analysis for a magnetic levitation platform used to determine the densities of microparticles, is presented. With this program, by processing the images of the magnetic levitation platform, the positions of the microparticles on the platform can be determined and the corresponding density values can be found. Thus, the densities of microparticles can be detected automatically at a resolution of 0.27 mg/mL.