Digital PCR chip, and droplet generation system and detection system containing same

A droplet generation system for digital PCR detection, comprising:

• a PCR chip;
• a microchannel comprising a water phase and having a first opening and a second opening for liquid to enter and exit;
• a rotation driving mechanism for driving the microchannel to reciprocating swing;
• and
• a fluid driving mechanism for driving the liquid to pass through the microchannel;
• wherein the PCR chip comprises:
• a chip body having a droplet storage cavity, wherein a bottom surface of the droplet storage cavity is flat;
• a containing cavity filled with oil standing on an upper surface of the chip body, wherein the microchannel is inserted into the containing cavity to inject the water phase into the oil such that droplets are generated within the containing cavity;
• a liquid inlet having a height of 5 mm to 15 mm for the droplets generated within the containing cavity to enter into the droplet storage cavity, the liquid inlet being provided in the chip body and located at a bottom of the containing cavity;
• and
• a first channel connecting the liquid inlet to the droplet storage cavity,
• a liquid outlet provided in the chip body;
• and
• a second channel connecting the liquid outlet to the droplet storage cavity;
• wherein, the first channel has a first internal pathway located inside the chip body, and the second channel has a second internal pathway located inside the chip body;
• wherein the chip body comprises a chip cover plate that is a flat plate and a chip substrate having a recess, wherein the flat plate and the recess are superimposed and compressed to form the droplet storage cavity, the first channel and the second channel;
• wherein the recess on the chip substrate comprises an opening that faces upward, the chip substrate is located below the chip cover plate, and the chip substrate and the chip cover plate are respectively made of plastic;
• wherein a plurality of chip units are arranged on the chip body, and each chip unit of the plurality of chip units comprises the droplet storage cavity, the first channel, and the second channel;
• a section of the droplet storage cavity is square or rectangular, a first communication opening and a second communication opening of the droplet storage cavity are respectively arranged at two opposite corners of the droplet storage cavity, the first internal pathway and the second internal pathway are respectively arranged on two opposite sides of the droplet storage cavity, the first communication opening is in communication with the first internal pathway, and the second communication opening is in communication with the second internal pathway;
• the first internal pathway is formed by inner spaces of one straight extension section and one arc extension section, the straight extension section starting at the liquid inlet, which is located outside the droplet storage cavity, and extending from the liquid inlet parallel to one side of the droplet storage cavity, and one end of the straight extension section is bent and extended toward the droplet storage cavity to form the arc extension section, and an end portion of the arc extension section away from the straight extension section opens into the droplet storage cavity;
• wherein droplets generated in the containing cavity deposit to a bottom of the containing cavity due to gravity and enter the first channel through the liquid inlet.