Seven Tips for Tail Vein Injection in Mice

Mouse Injection, a commonly used injection method in pharmacological, and toxicology experiments, sometimes requires rapid and accurate injection. But how to perform in the right way? This post gonna give you seven tips for a perfect injection.

1. Fix the mouse

Mouse fixator is preferred. Pores in the front to ensure the mouse breathing and holes in the back to pull out the tail. Do not leave too much space for the mouse or it will tamper during injection. Add some filler, if the space is too large.

2. Preparation of tail vein

Heat the tail of the mouse in about 50 °C water to expand the veins.

3. Selection of the tail vein

There are three tail veins in the tail of the mouse. One on the back and two on each side. As the one on the back is deep and thin, veins on the side are generally preferred.

4. Selection of syringe

Select 1–2ml syringe and №4 or №4.5 needle. One-time 2ml syringe for vaccination is preferred. The air should be pushed out to prevent mouse death caused by air in the vein after the syringe is inhaled.

5. Injection

Disinfect the tail with 75% alcohol. Inject in the 1/3 to 1/2 of the distal tail, where the skin is thin and the blood vessels are clear. And once failed, you can have more near choices. Tightly press the tail on the table with your left hand and make the needle (in your right hand) parallel to the table; make the tip slightly down before injection and slightly up once entered. If the needle advances in the blood vessels, you can feel there’s no resistance. If not, you can feel the needle does not advance smoothly. Keep in mind: do not inject too deep at first. Put the needle slightly upward once the needle is injected in the the skin.

6. Characteristics of Successful Injection

The difference between liquid injection into the vein and non-venous: there’s almost no resistance to push the fluid and it can be quickly finished. Usually 600ul can be pushed in 10 seconds. If injected in non-venous area, there would be greater resistance and there will be a dew-like exudate around the injection site. It will bleed less when pull out the needle. And because the liquid stasis in the tail, leading to poor blood flow, and tail ischemia, which will easily lead to tail inflammation and necrosis.

7. Wound treatment

Press the pin with gauze until bleeding tops. Usually for 5–10 minutes. This will help restore the wound as soon as possible in order to facilitate the next injection.

Collected by Creative BioMart.