Animal Protocol: Intravenous Injection in Mice


Welcome to our blog post on the animal protocol for intravenous (IV) injection in mice. In this article, we will guide you through the step-by-step process of performing an IV injection in mice, providing important tips and considerations along the way. Conducting experiments involving IV injections in mice requires precision and attention to detail to ensure accurate results and to minimize discomfort to the animals. By following this protocol, you can ensure the safety and welfare of the mice while optimizing the outcomes of your experiments.


Before starting, make sure to gather the following materials:

  • Sterile gloves
  • Syringe
  • Needles (22-26 gauge)
  • Alcohol swabs
  • Phosphate-buffered saline (PBS)
  • Sterile saline solution
  • Anesthetic agent (e.g., isoflurane)
  • Animal restrainer or anesthesia induction chamber


Follow these steps to perform an intravenous injection in mice:

  1. Prepare the solution: Dilute the substance to be injected in sterile saline or PBS, ensuring the desired concentration is achieved. Keep the solution ready.
  2. Prepare the animal: Place the mouse in an anesthesia induction chamber or a restrainer. Apply isoflurane or another approved anesthetic agent to induce anesthesia. Monitor the depth of anesthesia by checking the absence of paw withdrawal reflex.
  3. Prepare the injection site: Apply alcohol swabs to disinfect the injection site, usually the tail vein or lateral tail vein. Allow the area to dry.
  4. Draw the solution into the syringe: Using a sterile syringe, draw the desired volume of the prepared solution. Attach the appropriate gauge needle to the syringe.
  5. Perform the injection: Gently grasp the mouse’s tail and locate the vein. Insert the needle into the vein at a slight angle, taking care to avoid piercing through both sides of the vessel. Slowly inject the solution, observing for any adverse reactions.
  6. Remove the needle: Once the injection is complete, withdraw the needle carefully and apply gentle pressure to the injection site using a sterile gauze pad to prevent bleeding.
  7. Monitor the mouse: Place the mouse in its cage, ensuring it is kept warm and comfortable during recovery. Monitor the animal until it fully regains consciousness, ensuring it can move and eat without difficulty.


Here are some important considerations to keep in mind when performing intravenous injections in mice:

  • Ensure that the injection volume does not exceed 10% of the animal’s body weight to prevent fluid overload.
  • Use the appropriate needle size and gauge for the mouse strain and injection site to minimize injury.
  • Always maintain aseptic technique to prevent infections and contamination.
  • Handle the mice gently and calmly to minimize stress and discomfort.
  • Dispose of needles and syringes properly in designated sharps containers following institutional guidelines.


Intravenous injection in mice is a crucial technique in preclinical research. By following this animal protocol, you can perform intravenous injections safely and efficiently, ensuring reliable experimental outcomes while prioritizing the welfare of the animals involved.

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