大鼠尾静脉注射 z-bo 2020-10-14 299

　　Tail vein injection in rats is a common operation, but it is a bit difficult, but if there is no guidance, it may be a little confusing at first. However, as long as the method is mastered, it can be said that tail vein injection in rats is still very easy. In general, tail vein injection is very difficult in rats and mice. After being proficient, rats should be easier to inject than mice. Rats have thick tails and thick blood vessels, which makes it easier for you to understand how the needle is inserted. However, as the rat gets older, the tail becomes thicker. At this time, injection into the tail vein becomes more difficult. The needle tip should choose the gap between the two scales to facilitate the smooth puncture of the needle.

　　Steps:

　　1. First, fix the mouse. The easiest way to immobilize a mouse is to anesthetize it. After that, the mouse can stop and operate smoothly. However, anesthesia usually requires multiple or single doses, and the effects of anesthesia on experimental results and animals must be considered, and must be corrected in other ways.

　　Some fixing methods are similar to those of a mouse. If possible, make a metal cylinder (you can make one at your local blacksmith, or you can buy a customized one at the Shirotetsu store). First, metal is relatively strong and usable. Because it is fixed on the ironing board, it is easy to operate. Part of the cylinder has a removable cover, and there is a small hole in the center of the cover for the mouse's tail to extend (the middle hole is wrapped with tape, so that the sharp edge cuts the mouse's tail. It can be prevented). The other part may be made of a metal mesh, and the shape of the mesh may be the shape of a bullet. The mesh structure allows light to penetrate closer, making it easier for mice to penetrate the cylinder. The length of the cylinder is about 15 to 20 cm, and the diameter is about 5 to 8 cm. It can be a series of cylinders of length and diameter, suitable for mice of various sizes. During the operation, fix the gas cylinder on the iron frame, pull out the cover at the other end, make the side of the barbed wire slightly upward, grab the mouse’s tail, hang the mouse, and then make the mouse’s head round cylinder. Come closer. With a little guidance, the mouse drilled a hole in the cylinder so that the mouse's tail passed through the small hole in the center of the lid, closed the lid, straightened the mouse's tail outward, and proceeded to the next step. ..

　　You can also use the tricky wire covered with a squirrel cage to fix the mouse directly on the upper mouse. This is the job of the master. If you need an intravenous injection or two, you can try it.

　　2. After fixing the mouse, the injection will begin. Usually, a 5 ml disposable syringe is used to remove the needle, connect it to a 5.5 gauge scalp needle, and then pierce it with a scalp needle. Personally, it is more convenient and easier to fix the needle.

　　3. The blood vessels of rats must be filled before injection. You can use 75% alcohol cotton ball wiping method or hot water soaking method. If the blood vessels of rats are very fuzzy, it is recommended to use warm water soaking method. Do not heat the water to high temperature. After soaking in warm water for 2-3 minutes, remove the tail of the rat and wipe it with a dry cotton ball. please wait a moment. After filling the blood vessel, you can wipe it with an alcohol cotton ball, and then insert the needle. If the blood vessels are not full, you can soak them in warm water repeatedly. In addition, unless you are skilled, do not risk injections.

　　4. There are 4 blood vessels in the tail of a rat. It is generally believed that the left and right 2 veins are easy to inject. These 2 veins are often used for injection. Generally, the injection site should be near the tail of the rat. If the injection fails, the injection point can be selected upwards. However, do not place the needle too low, because the lower the vein, the thinner the vein and the more difficult it is to operate. Generally, it is recommended to lower the tail of the rat by a third.

　　5. The most important thing is to take the needle. When inserting the needle, the operator’s left index finger and thumb fix the tail of the mouse. The tail of the mouse passes through the thumb and then bends downward, and the needle insertion point is located near the paw of the thumb. The angle between the needle and the blood vessel is approximately 30°, and the needle tip is inclined upward so that it is immediately parallel to the blood vessel after lightly piercing the skin. Usually, it can be inserted into a blood vessel immediately. If you see clear blood return, you can inject a drug solution. Usually, there is no obvious resistance during the injection, and the blood vessels will not swell. The movement when pushing the fluid should be gentle. If the blood vessel is swollen, it means that the needle has not penetrated the blood vessel, and the needle should be immediately removed and re-injected. (Under normal circumstances, blood reflux can be seen. Without blood reflux, 90% of the blood will not enter the blood vessel. Do not press the drug. Injection of the drug will cause edema under the skin of the rat’s tail. Pull out the needle and pierce it again, To prevent it from puncturing, be extra careful when using colored liquids (such as Evansland)

　　6. Pull out the needle gently after injection. Use a dry cotton ball to push the needle tip to prevent liquid leakage.