Dept. of Chemical Engineering, Indian Institute of Technology Delhi, Hauz Khas 110016, India.
Dept. of Chemical Engineering, Indian Institute of Technology Delhi, Hauz Khas 110016, India.
Biosens Bioelectron. 2018 Jul 15;111:159-165. doi: 10.1016/j.bios.2018.04.005. Epub 2018 Apr 7.
Microarray technology to isolate living cells using external fields is a facile way to do phenotypic analysis at the cellular level. We have used alternating current dielectrophoresis (AC-DEP) to drive the assembly of live pathogenic Salmonella typhi (S.typhi) and Escherichia coli (E.coli) bacteria into miniaturized single cell microarrays. The effects of voltage and frequency were optimized to identify the conditions for maximum cell capture which gave an entrapment efficiency of 90% in 60 min. The chip was used for calibration-free estimation of cellular loads in binary mixtures and further applied for rapid and enhanced testing of cell viability in the presence of drug via impedance spectroscopy. Our results using a model antimicrobial sushi peptide showed that the cell viability could be tested down to 5 μg/mL drug concentration under an hour, thus establishing the utility of our system for ultrafast and sensitive detection.
利用外部场将活细胞分离出来的微阵列技术是在细胞水平上进行表型分析的一种简便方法。我们使用交流介电泳（AC-DEP）将活的致病性伤寒沙门氏菌（S.typhi）和大肠杆菌（E.coli）细菌组装成微型单细胞微阵列。优化了电压和频率的影响，以确定最大细胞捕获的条件，在 60 分钟内获得了 90%的捕获效率。该芯片用于在二元混合物中进行无校准的细胞负载估计，并进一步通过阻抗谱法用于快速和增强药物存在下的细胞活力测试。我们使用模型抗菌寿司肽的结果表明，在一小时内可以测试到 5μg/mL 药物浓度下的细胞活力，从而确立了我们的系统用于超快速和灵敏检测的实用性。
