This information is provided as an example protocol. Always be sure that IACUC or ethic committee approval is in place before beginning any experimental protocol.

The most accessible vessels for intravenous administration (IV injection) in mice are the veins that run the length of both lateral aspects of the tail.

Materials

• Sterile 26 G needle
• Sterile 1 mL syringe
• Heating device
• Mouse restraining device
• Gauze

Procedure

1. Weigh the mice before injection. Up to 1% of the animal’s body weight in volume can be administered per injection.
2. Use a heating device to warm the mice for 5-10 minutes to dilate the veins.
3. If using a mouse restraining device, anesthetizing the animals is not necessary. Place the mouse on the restraining device.
4. Grasp the tail at the distal end with the index and middle fingers of your non-dominant hand placed around the tail below the base.
5. Hold the lower part of the tail between the thumb and ring fingers.
   
6. Apply slight pressure with both set of fingers to straighten and stabilize the tail.
7. Hold the syringe with your dominant hand and insert the needle bevel up into the vein in the area between both set of fingers.
8. Push the agent slowly into the vessel without disrupting the needle in the vein.
9. If there is resistance or a blister-like area appears above the needle on the tail, remove the needle and re-insert above the first site.
10. Remove the needle and apply gentle compression until bleeding stops.
11. Return the animal to their cage and observe to make sure that the bleeding has not resumed.