实验小鼠 z-bo 2020-08-13 584

　　Principle of the experimental method: The blood-brain barrier is composed of the pia mater, the capillary wall of the choroid plexus and the glial membrane formed by the glial cells outside the wall. It acts as a natural barrier and can block pathogenic microorganisms, toxic products, and foreign bodies. Particles including dye particles enter the brain tissue and cerebrospinal fluid from the bloodstream, thereby protecting the central nervous system from damage.

　　Experimental materials: 2 mice

　　Reagents and kits: 1. 5% trypan blue aqueous solution 2. normal saline 0.1ml

　　Instruments and consumables: 1. 1ml sterile syringe (with No. 4 needle) 2. Ophthalmic scissors and tweezers, etc.

　　Experimental steps: 1. Use a 1ml sterile syringe to draw 5% trypan blue water solution into two mice through the tail vein, 0.7ml each, change the syringe, and inject 0.1ml physiological saline into one of the mice. 2. After 5-10 minutes, observe the color changes of the mouse skin, especially the eyes and mouth. 3. In 30-60 minutes, the eyes and mouth of the mouse were seen blue, that is, died of suffocation, and the abdomen was fixed downward. 4. Cut the skin along the dorsal midline from head to tail to expose the subcutaneous, muscle and internal organs and observe the color change. 5. Carefully dissect the skull and vertebrae, expose the brain and spinal cord, and compare with subcutaneous, muscle and internal organs; and compare the differences between the two mice. Matters needing attention 1. Trypan blue aqueous solution can only be used after filtering. 2. For tail vein injection, the needle should be inserted remotely; if the bolus is easy, it means that it has entered the blood vessel; if it causes subcutaneous bulging or whitening, it means that it has not entered the blood vessel; pull out the needle and insert the needle from a little closer.