Development of on-chip electrical measurement method for single cell
physical properties using femtosecond laser-induced impact force
所属：奈良先端科学技術大学院大学 博士後期課程 2 年（助成時）同上 博士後期課程 3 年（現 在）
氏名：TANG TAO■ 要約Single-cell analysis is crucial in the study of population heterogeneity, the identification ofminorities, and discovering unique characteristics of individual cells. To gain more efficient access tocell properties through microfluidic devices, in this research, we proposed, designed, and developed
an impedance cytometry system integrated with a femtosecond laser to characterize the physicalproperties of single cells. At present stage, we have succeeded in measuring a few characteristics (suchas size, shape, the mass and distribution of intracellular components) of a few types of individual cells.
By further improving the system, more different characteristics of cell could be achieved.
■ 結果と考察The entire research could be separated into
different parts due to its basic functions:
1. Label-free shape quantification for single
cellsFirst of the work, we developed theimpedance cytometry with the FPGA board,which has the capability of measuring single
cells with a throughput of thousands of cells
in a second, as shown in Fig. 1. We found that
there is a relationship between the cell shapeand the tilting level of impedance pulses.
Therefore, we proposed a new metric,
namely tilt index to quantify the shape ofsingle cells without optical devices.
2. Label-free detection for cell interior
Based on the previous work, we didfurther research into the high-frequency
detection of impedance cytometry. And we
found that the high-frequency impedanceFig. 1: Microscopic impedance cytometry forquantifying single-cell shape researchdetection could be used to analyze the intracellular
distribution. Besides, we proposed that the lowfrequency impedance detection can be employed tocharacterize the cell volume and shape (e.g., 0.5 MHz
in this work)., and high-frequency detection can beused for interior characterization and quantification.
Intracellular uneven distribution is related to the tilting
level of high-frequency impedance pulses (e.g., 6 MHz
in this work). This work has been selected as the backcover of the Lab on a Chip, as shown in Fig. 2.
As the high-frequency current can cross the cellmembrane, we also reported that the electric opacity is
positively associated with the intracellular density. The
loss of intracellular components is induced using
certain methods. Electrical opacity decreases as
intracellular density decreases.
3. Femtosecond laser-based single cell manuscript
Fig2: Cover page of Lab on a Chip
Aimed at the control of the femtosecond laser
pulses, we developed a control system based on a FPGA board (ALINX, AXU9EG), as shown in Fig.
3. Through the developed system, we can determine the number of femtosecond laser pulses based on
the amplitude of trigger system. This system can be integrated with several types of detection system
for the single cell manipulation in the microchannel, like the forementioned impedance detection
system or the fluorescence
detection system. With thecapability of controllingthe femtosecond laser
pulses, the force acting on
the single cells is also
controllable for us, whichenabled us to characterize
the properties of single
cells in a more efficientway.
Fig3: FPGA-based control system for femtosecond laser pulses■ 研究成果(1) Tang et al. Sensors and Actuators B: Chemical, 358, 131514. (2022). (IF: 7.46)(2) Tang et al. Lab on a Chip, 22, 550-559. (2022). (IF: 6.799)(3) Tang et al. Biosensors and Bioelectronics 193, 113521. (2021). (IF: 10.618)