Dual-frequency impedance assays for intracellular components in microalgal cells
Dual-frequency impedance assays for intracellular components in microalgal cells
复制标题
DOI：
10.1039/d1lc00721a
复制
发表时间：
2021-11-18
期刊：
影响因子：
6.1
通讯作者：
Yalikun, Yaxiaer
中科院分区：
文献类型：
--
作者：
Tang, Tao;Liu, Xun;Yalikun, Yaxiaer
亚微米水平的细胞内成分（包括细胞器和生物分子）通常通过特殊制备或昂贵的设置进行原位分析。在这里，一个无标记和成本效益的方法筛选微藻单细胞在亚细胞分辨率的基础上阻抗细胞术。据我们所知，这是第一次，阻抗信号和亚微米细胞内细胞器和生物分子之间的关系。以纤细裸藻（Euglena gracilis，E.在不同孵育条件下孵育的股薄肌）细胞（即，需氧和厌氧）和15 μ m聚苯乙烯珠（参照）在两种不同的刺激频率下（即，500 kHz和6 MHz）。基于以每秒约900个细胞的通量对数万个样品进行阻抗检测，使用三个度量来跟踪样品的生物物理性质的变化。结果，在显微镜下观察到，细胞的电直径显示出细胞体积和细胞内成分的明显收缩。阻抗脉冲的形态度量（即，倾斜指数）成功地表征了细胞形状和细胞内组成分布的变化。此外，电不透明度显示细胞内组分与细胞体积的比例在细胞自我调节下保持稳定。此外，模拟用于支持这些发现，并阐明亚微米细胞内成分和细胞形态如何影响阻抗信号，为未来的改进提供了基础。这项工作开辟了一个无标记和高通量的方式来分析单细胞的细胞内成分的阻抗细胞仪。
Intracellular components (including organelles and biomolecules) at the submicron level are typically analyzed in situ by special preparation or expensive setups. Here, a label-free and cost-effective approach of screening microalgal single-cells at a subcellular resolution is available based on impedance cytometry. To the best of our knowledge, it is the first time that the relationships between impedance signals and submicron intracellular organelles and biomolecules are shown. Experiments were performed on Euglena gracilis (E. gracilis) cells incubated under different incubation conditions (i.e., aerobic and anaerobic) and 15 mu m polystyrene beads (reference) at two distinct stimulation frequencies (i.e., 500 kHz and 6 MHz). Based on the impedance detection of tens of thousands of samples at a throughput of about 900 cells per second, three metrics were used to track the changes in biophysical properties of samples. As a result, the electrical diameters of cells showed a clear shrinkage in cell volume and intracellular components, as observed under a microscope. The morphology metric of impedance pulses (i.e., tilt index) successfully characterized the changes in cell shape and intracellular composition distribution. Besides, the electrical opacity showed a stable ratio of the intracellular components to cell volume under the cellular self-regulation. Additionally, simulations were used to support these findings and to elucidate how submicron intracellular components and cell morphology affect impedance signals, providing a basis for future improvements. This work opens up a label-free and high-throughput way to analyze single-cell intracellular components by impedance cytometry.