Capillary tube sampling system and method and single-cell electrical characteristic detection system

Abstract

The invention provides a capillary tube sampling system and method and a single-cell electrical characteristic detection system. The capillary tube sampling system comprises an injection pump, a capillary tube, a micro-fluidic chip and a negative-pressure module, wherein a compression channel, a cell recovery channel and a negative-pressure channel are sequentially formed in the micro-fluidic chip and constitute a micro-channel of the micro-fluidic chip; the front end of the compression channel is taken as a liquid inlet of the micro-channel, the rear end of the compression channel is connected to a liquid outlet of the micro-channel through the cell recovery channel and the negative-pressure channel, and the negative-pressure module is connected to the liquid outlet of the micro-channel; the rear end of the capillary tube is connected to the injection pump, inhalation and discharge of a cell suspension are controlled by the injection pump, and the cell suspension dropped in from one side of the liquid inlet of the micro-channel by the capillary tube sequentially enters the compression channel and the cell recovery channel under the action of the negative pressure provided by the negative-pressure module. According to the capillary tube sampling system and method and the single-cell electrical characteristic detection system, the loss rate of samples can be effectively reduced, the high recovery rate can be realized, and the single-cell electrical characteristic detection system can be used for electrical characteristic detection of cell samples with extremely small quantity of cells.

Description

technical field [0001] The invention relates to the field of microfluidic technology, in particular to a capillary sampling system, a sampling method, and a single-cell electrical characteristic detection system. Background technique [0002] Single-cell electrical properties, such as cell membrane specific capacitance and cytoplasmic conductivity, are of great significance and potential value for understanding cell function and state. As a marker-free cell feature, it can be used to define and classify cells. [0003] In the study of single-cell electrical properties, the cell is equivalent to a capacitor-resistance network, in which the cell membrane with a bilayer phospholipid structure is equivalent to a capacitor, and the cytoplasm mainly composed of electrolytes is equivalent to a resistor. Considering that cells vary in size, cell-to-cell comparisons can only be made using cell membrane capacitance per unit area and cytoplasmic conductivity that are independent of ce...

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Problems solved by technology

In this type of method, the flow channel is a non-compressed channel (that is, the cross-sectional area of ​​the channel is smaller than the cross-sectional area of ​​the cell). Although the throughput is greatly improved, the leakage current between the electrodes in the test system is large and there is a lack of electrical models. , the electrical properties of single cells independent of cell size cannot be obtained

[0007] In addition, based on the pure microfluidic technology of the compressed channel, the cells in the microfluidic sampling channel are driven by negative pressure to flow through a process whose cross-sectional area is smaller than that of the compressed channel, and the stretched length of the cells and the impedance at both ends of the compressed channel are measured, combined with electrical The model obtains single-cell electrical characteristic parameters. Although a certain throughput of single-cell electrical characteristic parameters independent of cell size can be obtained, the cell loss rate is high due to the existence of fluid dead zones in the microfluidic sampling channel, and a large investment is required. The number of cells measured is two to three orders of magnitude larger than the number of cells, and many cells, such as circulating tumor cells (CTCs), are rare and cannot provide a large number of cells for testing

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