Cell dielectrophoretic responses have been extensively studied for biomarker expression, blood typing, sepsis, circulating tumor cell separations, and others. Surfactants are often added to the analytical buffer in electrokinetic cellular microfluidic systems to lower surface/interfacial tensions. In nonelectrokinetic systems, surfactants influence cell size, shape, and agglomeration; this has not been systematically documented in electrokinetic systems. In the present work, the impacts of the Triton X-100 surfactant on human red blood cells (RBCs) were explored via ultraviolet-visible spectroscopy (UV-Vis) and dielectrophoresis (DEP) to compare nonelectrokinetic and electrokinetic responses, respectively. The UV-Vis spectra of Triton X-100 treated RBCs were dramatically different from that of native RBCs. DEP responses of RBCs were compared to RBCs treated with low concentrations of Triton X-100 (0.07-0.17 mM) to ascertain surfactant effects on dielectric properties. A star-shaped electrode design was used to quantify RBC dielectric properties by fitting a single-shell oblate cell model to experimentally-derived DEP spectra. The presence of 0.07 and 0.11 mM of Triton X-100 shifted the RBC's DEP spectra yielding lower crossover frequencies ( f C O ) . The single-shell oblate model revealed that cell radius and membrane permittivity are the dominant influencers of DEP spectral shifts. The trends observed were similar for 0.11 mM and 0.07 mM Triton X-100 treated cells. However, a further increase of Triton X-100 to 0.17 mM caused cells to only exhibit negative DEP. The magnitude of the DEP force increased with Triton X-100 concentration. This work indicates that dynamic surfactant interactions with cell membranes alter cell dielectric responses and properties.

中文翻译：

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低浓度表面活性剂对红细胞介电泳反应的影响。

已经针对生物标志物的表达，血型，败血症，循环肿瘤细胞分离等进行了广泛的细胞介电泳反应研究。通常将表面活性剂添加到电动细胞微流体系统的分析缓冲液中，以降低表面/界面张力。在非电动系统中，表面活性剂会影响细胞的大小，形状和聚集。在电动系统中尚未对此进行系统记录。在目前的工作中，通过紫外线-可见光谱法（UV-Vis）和介电电泳法（DEP）探索了Triton X-100表面活性剂对人红细胞（RBC）的影响，以分别比较非电动和电动反应。经Triton X-100处理的RBC的UV-Vis光谱与天然RBC的光谱有很大不同。将RBC的DEP响应与用低浓度Triton X-100（0.07-0.17 mM）处理的RBC进行比较，以确定表面活性剂对介电性能的影响。通过将单壳扁形细胞模型拟合到实验衍生的DEP光谱，星形电极设计用于量化RBC介电性能。0.07和0.11 mM的Triton X-100的存在改变了RBC的DEP光谱，从而产生了较低的交叉频率（f CO）。单壳扁圆模型显示，细胞半径和膜介电常数是DEP光谱位移的主要影响因素。对于0.11 mM和0.07 mM Triton X-100处理的细胞，观察到的趋势相似。但是，Triton X-100进一步增加到0.17 mM导致细胞仅显示负DEP。DEP力的大小随Triton X-100浓度的增加而增加。