Colonoscopic Guided Murine Wound Model: A Method to Isolate Biopsy Induced Wound Bed from Colon to Understand the Healing Process

At the appropriate experimental endpoint, open the skin and abdominal muscle layers to expose the body cavity of the experimental animal, and place closed forceps under the colon. Gently lift the colon to release it from the underlying mesentery, and cut the tissue at its midpoint and at the anus to collect it from the mouse.

Use a 20-milliliter syringe filled with ice-cold PBS, and equipped with a rat gavage needle, to flush out the fecal contents; and place the cleared colon onto a piece of filter paper. Open the colon longitudinally, taking care that the mesenteric side is face down against the filter paper, and use a Pasteur pipette to cover the mucosa with 0.2% methylene blue.

After a few seconds, drain off the excess stain and view the colon under a dissecting microscope to locate the wound bed. Use 4-inch micro iris scissors to cut around the edge of the bed, being careful not to cut into the muscle layer, and use fine point tweezers to transfer the dissected tissue into a tube for snap freezing and/or storage.