Principle of Cell Chemotactic Experiment Definition: Chemotactic (Chemotaxis, also known as chemical chemotactic) is One refers to the movement of body cells, bacteria, and other single-cell, multi-cell organisms based on certain chemicals in the environment. This is very important for bacteria to find food (such as glucose), so that bacteria will tend to places where there is a high concentration of food molecules, or away from places that are toxic (such as phenol). In multicellular organisms, chemotaxis is as essential for its development as for other normal functions. Positive chemotaxis refers to movement towards higher chemical concentrations, while negative chemotaxis is the opposite. 2. The main problems of the current cell chemotaxis experiment method Currently, this experiment method is generally used: do with transwell, as shown in the figure below, place the inducer in the lower space, put the cells in the upper space, and after a certain time, count the number of cells that penetrate into the lower space ( Stain the cells or wipe them down and count). The more cells that penetrate into the lower part, the stronger the tropism, and then the chemotaxis result of the cell is obtained. The main problems: (1) Due to the limitation of the working distance of the microscope, it is impossible to use a microscope for real-time observation, and it is impossible to record the chemotaxis process of the cell. If the chemotaxis process of the cell can be recorded and recorded in real time, the experimental results are more intuitive. (2) Using the end point measurement method, transwell can only count the number of cells that eventually penetrate the lower chamber, and the speed of cell movement cannot be examined. (3) Unstable concentration gradient. Transwell needs to make a series of holes to complete the concentration gradient chemotaxis experiment. Because transwell can only place a fixed concentration in the lower chamber, a series of concentration gradients must be made. Make a few wells (for example, set 2, 4, 6, 8 unit concentration for each well, which is a gradient of 2, 4, 6, 8); the purpose of the concentration gradient in this experiment is to see if the cells are indeed in the inducer. Stronger or weaker tropism (or a change in tropism depending on the concentration of the inducer). (4) Non-physiological experimental environment.
