Cell Separation with Hybrid Magnetic Levitation-Based Lensless Holographic Microscopy Platform

Abstract

Separation of target cells in a heterogeneous solution is of great importance for clinical studies especially for immunology and oncology. Separated cells can be used for diagnostic applications ranging from whole blood counting to isolation of circulating tumor cells (CTC) for personalized medicine. Recent separation technologies rely on labelling and identifying target cells with variety of labelling principle such as fluorescence or magnetic tags. However, they require laborintensive processes, long analysis time, and expensive chemical reagents and instrumentation. Hence, their usage is limited to wellequipped centralized laboratories. There is a need for a rapid, sensitive, low-cost and automated cell separation technology to disseminate usage of this technology even in rural areas. Magnetic levitation is a powerful cell separation method, which distinguishes cells based on their levitation heights depending on cell density. However, magnetic levitation-based separation technologies require traditional, bulky and expensive microscopes for analysis. Lensless digital inline holographic microscopy (LDIHM) systems are composed of a simple illumination system containing an LED, a pinhole, and an imaging sensor for high-resolution microscopic imaging, which eliminates needs of highly fragile and expensive optics as in traditional microscopy. Here, we introduced a novel hybrid and portable cell separation platform, where magnetic levitation technology is integrated with LDIHM system for automated analysis of cell levitation heights. Using this platform, three different cell lines are successfully separated. Live and dead cells having distinguished levitation heights can be also identified in the platform.

Transformer oil quality assessment based on lens-free holographic microscopy

“…It can obtain a hologram with a large field of view of the transformer oil sample through lens-free experiment, and extract the size and quantitative phase information of gas bubbles in the transformer oil sample from the hologram. Then the information on the area, volume, amount, and gas to oil volume ratio of the gas bubbles in transformer oil can be calculated to evaluate the quality of transformer oil [18][19][20][21].…”

Axial-circular magnetic levitation assisted biofabrication and manipulation of cellular structures

“…paramagnetic hemoglobin containing blood cells and magnetotactic bacteria), move towards regions of the high magnetic field (positive magnetophoresis) [11]. However, most cell types are diamagnetic in nature, and once placed into a surrounding environment with high magnetic susceptibility, they are repelled towards the minimal magnetic field (negative magnetophoresis, also referred to as diamagnetophoresis) [12][13][14][15][16][17]. Stable cell trapping and selfassembly have been previously conducted by both positive and negative magnetophoresis to create viable 3D structures [18][19][20].…”

Magnetic levitation-based adipose tissue engineering using horizontal magnet deployment

“…Diamagnetic levitation, which is a technique working with the principle of removing of diamagnetic objects to lowest magnetic flux density produced by magnets [1], has been used for various biological applications such as density-based analysis, cell manipulation and 3D biofabrication [2][3][4][5][6][7]. One of the first applications of magnetic levitation system is detection of the cell density which is an indicator of cell state due to density changes occurred during some cellular processes such as differentiation, disease state, cell cycle and cell death [8].…”