Mammary fat pad transplantation of tumorgrafts

Two mice are anesthetized with isoflurane in the anesthesia chamber. Tumor grafts from a previous mouse are processed into 3-5 millimeter pieces and stored in PBS solution with penicillin and streptomycin, selecting only healthy viable tissue while avoiding necrotic regions.

The animal is positioned in the nose cone to receive continuous isoflurane anesthesia. Anesthesia depth is verified with a toe pinch test, and ketoprofen analgesic is administered to control post-operative pain.

The left mammary pad region and surrounding areas are shaved to expose the fourth mammary fat pad. The surgical site is sterilized using Povidone iodine swab sticks followed by sterile alcohol prep pads.

A small incision is made in the skin, and a 10-gauge trocar needle is used to create a guide path into the mammary fat pad, positioned at least one centimeter from the initial incision.

The tumor fragment is placed on the end of the trocar needle using sterile forceps. The needle is reinserted along the guide path and pushed to deposit the tumor piece into the fat pad pocket.

The skin is pulled tight with forceps and allowed to fall back naturally. The wound is closed using surgical staples that will remain in place for approximately one week.

The animal is removed from anesthesia and placed in a warmed cage to maintain body temperature. The animal is monitored until it regains consciousness and resumes normal activity.