To begin, place the anesthetized mouse on the surgical table. Using a cotton swab, apply the depilatory paste onto the skin, covering the masseter muscle and the tibialis anterior muscle. After waiting for one to two minutes, wash away the paste with a surgical wipe.
To expose the masseter muscle, first palpate along the inferior edge of the mandible. At five millimeters from the edge, cut open the skin along the line, connecting the oral commissure to the tragus. To perform freezing, use pre-cooled forceps to hold a piece of dry ice.
Place the dry ice along the long axes of the masseter muscles directly onto the surface of the muscle and hold for five seconds. Confirm that the muscle appears stiff and pale white immediately after removing the dry ice, and then returns to its normal color and texture within 22 to 25 seconds. After the muscle fully recovers, close the skin wound with at least three 7-0 sutures.
For the tibialis anterior muscle, palpate along the calf to locate the anterior edge of the tibia bone. Two millimeters posterior to the edge, cut open the skin, starting from the knee and ending at the ankle. To perform freezing, use pre-cooled forceps to hold a piece of dry ice.
Place the dry ice along the long axes of the tibialis anterior muscles directly onto the surface, and hold for five seconds. Confirm that the muscle appears stiff and pale white immediately after removing the dry ice, and then returns to its normal color and texture within 22 to 25 seconds. After suturing the skin wound, place the mouse on a heater plate maintained at approximately 38 degrees Celsius.
Monitor continuously until the mouse recovers its righting reflex.
