Application Cases

Experiment Name: Cell Sorting and Single-Cell Analysis Based on Microfluidic Technology for Tumor Drug Sensitivity Research

Research Direction: Biomedical

Experimental Principle:
An integrated microfluidic chip was constructed for rapid sorting and counting of circulating tumor cells (CTCs) from whole blood. The chip first utilizes inertial focusing principles to achieve rapid preliminary sorting of CTCs in a spiral channel, followed by further purification and concentration of CTCs using deterministic lateral displacement (DLD) principles. This chip enables rapid sorting of CTCs from whole blood, demonstrating advantages of high purity (92±3%) and high throughput (6 mL of whole blood per hour).

Testing Equipment:
Signal generator, ATA-1372A broadband amplifier, microfluidic chip, fluorescence microscope, oscilloscope.

Figure: Experimental Setup Diagram

Experimental Process:
Rapid capture of single cells can also be achieved using cell size or electrical, magnetic, acoustic, or optical properties. Dielectrophoretic (DEP) forces applied to cells enable the capture of larger tumor cells in each microwell within minutes. As shown in Figure 1-10A, the DEP force applied to cells is proportional to their size. Compared to smaller normal blood cells, larger tumor cells are preferentially captured in the microwells. The device consists of a microwell array chip and a glass plate coated with an indium tin oxide (ITO) film. Hundreds of thousands of microwells are patterned on a photoresist (SU-8) film, and a thin-film electrode (150 nm thickness, resistivity 10 Ω/sq) is formed on an ITO-coated glass substrate (70 mm × 40 mm × 1 mm), ensuring that the ITO electrode is located at the bottom of each microwell. When an alternating voltage (frequency: 100 kHz–10 MHz, potential: 20–50 Vp-p) is applied between the electrodes, a non-uniform electric field with an intensity of 40–100 kV/m is generated in each microwell, enabling the capture of magnetically labeled cells.

Figure 1: Schematic Diagram of the Device

Experimental Results:
Single-cell alignment can be completed in less than 15 seconds. Additionally, after removing the external magnetic field and the tip holder, specific individual cells can be extracted using a micromanipulator for downstream analysis.

Aigtek ATA-1372A Broadband Amplifier:

Figure: Specifications of the ATA-1372A Broadband Amplifier