The analysis of cell electrophysiology for pathogenic samples at BSL3 can be problematic. It is virtually impossible to isolate infected from uninfected without a label, for example green fluorescent protein, which can potentially alter the cell electrical properties. Furthermore, the measurement of highly pathogenic organisms often requires equipment dedicated only for use with these organisms due to safety considerations. To address this, we have used dielectrophoresis to study the electrical properties of the human THP‐1 cell line and monocyte‐derived macrophages before and after infection with non‐labelled Mycobacterium tuberculosis. Infection with these highly pathogenic bacilli resulted in changes including a raised surface conductance (associated with reduced zeta potential) and increased capacitance, suggesting an increase in surface roughness. We have also investigated the effect of fixation on THP‐1 cells as a means to enable study on fixed samples in BSL1 or 2 laboratories, which suggests that the properties of these cells are largely unaffected by the fixation process. This advance results in a novel technique enabling the isolation of infected and non‐infected cells in a sample without labelling.

中文翻译：

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结核分枝杆菌感染改变了人类巨噬细胞的介电特性

BSL3 致病性样品的细胞电生理学分析可能存在问题。如果没有标签（例如绿色荧光蛋白），几乎不可能将感染者与未感染者分离，因为绿色荧光蛋白可能会改变细胞的电特性。此外，出于安全考虑，高致病性生物体的测量通常需要专用于这些生物体的设备。为了解决这个问题，我们使用介电泳来研究人类 THP-1 细胞系和单核细胞衍生的巨噬细胞在感染非标记物之前和之后的电特性。结核分枝杆菌。这些高致病性杆菌的感染导致了一些变化，包括表面电导升高（与 zeta 电位降低相关）和电容增加，表明表面粗糙度增加。我们还研究了固定对 THP-1 细胞的影响，作为在 BSL1 或 2 实验室中对固定样品进行研究的一种手段，这表明这些细胞的特性在很大程度上不受固定过程的影响。这一进步催生了一种新技术，无需标记即可分离样品中感染和未感染的细胞。