Kaphle Kishor, Nawarathna Dharmakeerthi
Department of Electrical and Computer Engineering, North Dakota State University, Fargo, ND 58105, USA.
Biomedical Engineering Program, Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23508, USA.
Biosensors (Basel). 2025 Jan 6;15(1):22. doi: 10.3390/bios15010022.
Cell lysis is the starting step of many biomedical assays. Electric field-based cell lysis is widely used in many applications, including point-of-care (POC) applications, because it provides an easy one-step solution. Many electric field-based lysis methods utilize micro-electrodes to apply short electric pulses across cells. Unfortunately, these cell lysis devices produce relatively low cell lysis efficiency as electric fields do not reach a significant portion of cells in the sample. Additionally, the utility of syringe pumps for flow cells in and out of the microfluidics channel causes cell loss and low throughput cell lysis. To address these critical issues, we suspended the cells in a sessile drop and concentrated on the electrodes. We used low-frequency AC electric fields (1 Vpp, 0-100 kHz) to drive the cells effectively towards electrodes and lysed using a short pulse of 10 V. A post-lysis analysis was performed using a hemocytometer, UV-vis spectroscopy, and fluorescence imaging. The results show that the pre-electric polarization of cells, prior to applying short electrical pulses, enhances the cell lysis efficiency. Additionally, the application of AC electric fields to concentrate cells on the electrodes reduces the assay time to about 4 min. In this study, we demonstrated that low-frequency AC electric fields can be used to pre-polarize and concentrate cells near micro-electrodes and improve cell lysis efficiency. Due to the simplicity and rapid cell lysis, this method may be suitable for POC assay development.
细胞裂解是许多生物医学检测的起始步骤。基于电场的细胞裂解因其提供了一种简单的一步解决方案，在包括即时检测（POC）应用在内的许多应用中被广泛使用。许多基于电场的裂解方法利用微电极对细胞施加短电脉冲。不幸的是，这些细胞裂解装置产生的细胞裂解效率相对较低，因为电场无法到达样品中很大一部分细胞。此外，使用注射泵使细胞流入和流出微流控通道会导致细胞损失和低通量细胞裂解。为了解决这些关键问题，我们将细胞悬浮在固定液滴中并集中在电极上。我们使用低频交流电场（1 Vpp，0 - 100 kHz）有效地将细胞驱向电极，并使用10 V的短脉冲进行裂解。使用血细胞计数器、紫外可见光谱和荧光成像进行裂解后分析。结果表明，在施加短电脉冲之前对细胞进行预电极极化可提高细胞裂解效率。此外，施加交流电场将细胞集中在电极上可将检测时间缩短至约4分钟。在本研究中，我们证明了低频交流电场可用于在微电极附近对细胞进行预极化和浓缩，并提高细胞裂解效率。由于方法简单且细胞裂解迅速，该方法可能适用于即时检测分析的开发。
