Microchip device with parallel operation for bacterial chemotactic analysis

- Novel system to analyze the bacteria chemotaxis is proposed and developed.
- Simple micro channel for analysis of the bacteria chemotaxis is designed.
- Bacteria number is measured as bacteria's capacitance between the two electrodes.
- Analysis of the bacteria chemotaxis without microscope is realized by integrated microchip.
- The effectiveness is confirmed by Escherichia coli and Vibrio alginolyticus.

In this study, we developed a novel microchip device system that enables the analysis of a large amount of bacterial chemotaxis data, which is one of the most fundamental behaviors of bacteria. Chemotaxis involves sensing of chemical gradients and behavioral adjustment by bacteria. In the proposed system, we conducted parallel analysis of bacterial chemotaxis without microscopic observation. We first confirmed that a simple microchannel could be used to analyze bacterial chemotaxis by microscopy. Next, we developed a system involving the photolithography technique and sputtering, and counted bacterial numbers without microscopic observation by measuring the capacitance between the two microelectrodes. Furthermore, we developed an integrated microchip for bacterial chemotactic analysis and successfully analyzed motile bacteria with single and parallel operation. This device may achieve large-scale analysis by parallel operation and may be useful for high-throughput analysis of unknown bacterial chemotaxis for identifying new attractants and repellents.