Prepare Mvein restrainers and a 100 ml bottle of luke warm water.
Load mouse head first into the restrainer.
Immobilize the mouse in restrainer by adjusting position of head cone, closing the front cover and loosely tightening the screws.
Warm the mouse’s tail by placing the Mvein restrainer on the beaker.
Rotate Mvein restrainer 90 degrees so that the tail is lifted in position for injection.
Prepare for insertion into tail vein by holding syringe in ‘aloha’ position with the bevel up. Use smaller syringes if necessary, for example, these ones (cat# 324702) from VWR.
Anchor hand on the restrainer and table while gently extending the mouse’s tail in place.
Gently insert the needle into the mouse’s lateral tail vein with the needle bevel up. The needle should easily slide up the vein without any resistance/back pressure when depressing the plunger vein with pinky.
Video of Tail Vein Injections with the Mvein™ Restrainer
The head cone of the Mvein™ restrainer invites the mouse to willingly and easily insert their entire head. The head cone of Mvein will not pinch off the nose of the animal causing them to asphyxiate like traditional nose cone based devices.
The rectangular shape of the restrainer provides space for flank tumors in one of the upper corners, prevents the mouse from rolling and allows technicians to simply place the restrainer on its side so the lateral tail vein is in the desirable superior position for injection.
Mice ranging between 10-45 grams can be restrained for up to 60 minutes, as tested.
The Mvein restrainer can be purchased online: https://www.medilumine.com/product/mvein-restrainer-for-mouse-tail-vein-injections/
Only give the screws an additional 1/8 turn when slight resistance is felt upon tightening. It is not necessary to over-tighten the screws on the device to keep the mouse immobilized.
The tail skin of C57BL/6 mice that are approximately 10 weeks of age becomes darker and it is more difficult to see the vessels. This can also be the case with sick, dehydrated or anemic mice.
It is important to note that the depth of the vein is slightly different at different locations on the tail.
It is recommended to be well rested and to limit coffee consumption before performing the procedure to avoid shaking during the injection. This is especially the case for experiments that require numerous tail vein injections
Learn more about MediLumine’s tail vein injection training course and services here: https://www.medilumine.com/services/