Magnetic‐activated cell sorting (MACS) using magnetic nanoparticles coated with specific antibodies is commonly used in immunology research. For in vitro isolation purposes, it is important to know to what extent the magnetic properties remain present in the isolated cell populations and whether it has consequences for sequential isolations. We hypothesized that only upon cell division, cells will lose their magnetic properties via dilution of the particles in/on their daughter cells. We analysed residual magnetic properties of cells that divided vs cells that did not divide after magnetic bead‐based cell separation. As a model, we isolated T cells using beads targeting the non‐modulating surface molecule CD45RO. Cells were labelled with the cell division tracking dye PKH and cultured under different conditions to induce variable degrees of cell division. We demonstrate that T cells that underwent no, or only minimal, cell divisions after MACS retained magnetic properties for up to at least 2 weeks of in vitro culture. The presence of nanoparticles was detected on their cell surface and intracellularly using Labeling Check reagent. These results have important consequences for procedures requiring repetitive isolation rounds after in vitro culture.

中文翻译：

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T细胞基于磁珠的细胞分离后的磁特性的长期体外持久性。

在免疫学研究中通常使用涂有特异性抗体的磁性纳米颗粒进行磁激活细胞分选（MACS）。为了进行体外分离，重要的是要知道分离的细胞群体中仍保留多大程度的磁性，以及它是否对顺序分离产生影响。我们假设只有在细胞分裂后，细胞才会通过稀释子细胞内/子上的颗粒而失去其磁性。我们分析了基于磁珠的细胞分离后分裂的细胞与未分裂的细胞的残余磁性能。作为模型，我们使用靶向非调节性表面分子CD45RO的珠子分离了T细胞。用细胞分裂追踪染料PKH标记细胞，并在不同条件下培养以诱导可变程度的细胞分裂。我们证明，MACS后没有或仅有最少细胞分裂的T细胞在至少2周的体外培养后仍保持磁性。使用Labeling Check试剂在细胞表面和细胞内检测到纳米颗粒的存在。这些结果对于需要在体外​​培养后进行重复隔离回合的操作具有重要的意义。