1. Number of experimental animals In the experiment, for the convenience of grouping and discrimination, it is often necessary to number the experimental animals in advance. The commonly used numbering methods are as follows: 1) Dye labeling method: Common dyes - red dye: 5% neutral red or magenta liquid; yellow dye: 3% ~ 5% picric acid solution; brown dye: 2% silver nitrate solution; black dye: coal tar ethanol solution. Marking rules - Animals are painted with different chemicals depending on the color of the animal's coat. Labeling methods for animals such as rabbits and dogs - use a brush to draw dye solutions of different colors and directly write numbers on the back of the animal. If it is painted with a silver nitrate solution, it should be exposed to sunlight for 1 minute. Rat, mouse markers - usually colored spots on different parts of the animal to indicate different numbers. 2) Piercing method: Use a special punch to punch holes or gaps in different parts of the animal's ear to indicate a certain number. This method is one of the commonly used labeling methods in mice. 3) Listing numbering method: This method is simple and practical, and is often used for the numbering of large animals such as dogs and monkeys. The number is stamped on a round or square metal plate, which is usually made of aluminum or stainless steel. Fix it on the collar or ear of the animal before the experiment. 4) Artificial acupuncture number method: first remove the animal coat, use a needle to puncture the number on the animal skin, and then apply it with ethanol ink. 2. Capture and fixation of experimental animals The correct grasping and fixing of experimental animals is to not damage the animal's health, affect the observation indicators, and prevent bites by animals, so as to ensure the smooth progress of the experiment. The method of grasping and fixing experimental animals depends on the content of the experiment and the type of animal. Before grasping fixed animals, you must have an understanding of the general habits of various animals. When grasping and fixing, you must be careful and careful, not rude, and be bold and agile, so as to correctly grasp the fixed experimental animals and not cause damage to the animals. purpose. 1) Mouse grasping fixation method The mouse is docile and generally does not bite. When grabbing, first grab the rat tail with your right hand and gently pull it back in the squirrel cage or the experimental bench. When crawling forward, grab the small thumb and forefinger with your left hand. For the ears and neck of the mouse, place the mouse in the left hand, straighten the hind legs, hold the rat tail with the ring finger, and hold the hind legs with the little finger. Experienced people directly use the left hand little finger to hook the rat tail, quickly pinch the thumb and index finger, middle finger to the back of the neck and back skin. This method of fixation in the hands allows for intragastric, subcutaneous, intramuscular, and intraperitoneal injections of experimental animals and other experimental procedures. For anatomy, surgery, cardiac blood sampling and tail vein injection, the mouse should be fixed in a certain form. The anatomical operation and blood sampling can make the animal take the dorso position first (if necessary, anesthesia first), then use the pin The front and rear limbs of the rat were fixed on the wax plate in turn. When the tail vein is injected, it can be fixed by the tail vein injection frame of the mouse. Firstly, according to the size of the animal, a suitable fixing frame is selected, and the mouse cap is opened, the tail of the mouse is handed, the animal head is aligned with the mouse mouth and sent into the tube, and the mouse is adjusted. After the length of the tube is suitable, the tail is exposed, and the end of the tube can be used for tail vein injection or tail vein blood collection. 2) Rat grasping fixation method The method of grasping rats is basically the same as that of mice, except that the rats are sharper than the teeth of the mice, and it is not easy to grasp by attack. Otherwise, they will be bitten. To avoid bites when grabbing, you can bring canvas gloves. If you are intraperitoneal, intramuscular, subcutaneous, etc., you can also use the left hand fixation method, just use the thumb and forefinger to pinch the mouse ear, and the remaining three fingers pinch the back skin of the mouse and place it in the left palm, so that the right hand can Perform various experimental operations. You can also stretch out the tiger's mouth of the left hand and grab it from the back. If surgery or dissection is required, it is necessary to anesthetize or kill beforehand, then use a fine cotton cord to tie the leg, and the back position is tied to the rat fixation plate; the tail vein is fixed with the same mouse (just change the holder to Rat fixed box can be). 3) Grab and fixation method for guinea pigs Guinea pigs are more timid and less likely to be irritated and frightened, so they must be stable, accurate and rapid when they are caught. The general method of grasping is: first fasten the back of the mouse with the palm of your hand, grasp the top of the shoulder, hold the neck with the thumb and forefinger ring, and hold the hip with the other hand. The fixed way is basically the same as the rat. 4) Rabbit It is gentler, but its claws are sharper and should be prevented from being scratched. Grab the skin on the back of the neck with one hand, gently lift the rabbit, and hold the buttocks with the other hand; or grasp the skin at the back of the neck and hold the rabbit by hand. The fixing method can be determined according to the needs of the experiment. For rabbit ear vascular injection, it can be fixed with rabbit box; if you want to do abdominal injection, surgery and blood pressure measurement, you need to fix the rabbit on the rabbit operating table. The rabbit head can be fixed with rabbit head clip. Yancheng Rongtai Labware Co.,Ltd , https://www.shtestlab.com