Colonoscopic Guided Pinch Biopsy in a Mouse Model: A Technique to Visualize and Extract Tissue Samples from Mouse Colon

Under pathological conditions, colonoscopy enables visualization of the colon and tissue extraction by pinch biopsy for detailed analysis of inflammatory wounds.

To perform colonoscopic-guided pinch biopsy in a mouse, begin with a biopsy assembly. The assembly contains a connector unit, an endoscope sheath with a pre-inserted colonoscope of optimal diameter. The colonoscope is connected to a light source, a video source, a gas port, and an instrument port for biopsy forceps.

Next, prepare an anesthetized mouse in the prone position on the colonoscopy platform. Pull the tail upward and use a gavage needle to infuse the anus with a suitable buffer to flush any fecal matter. Then, insert the colonoscope into the anus and advance it into the rectum. Continue moving the colonoscope further toward the colon while pumping gas to keep the colon inflated.

Next, steer the forceps out of the instrument port and open the jaws. Rotate the forceps at a right angle to induce a wound of optimal depth. Wounds that are too shallow or too deep result in a superficial wound or colon perforation, respectively. Thereafter, using biopsy forceps, pinch off the colon tissue. The extracted tissue and the induced wound can be further analyzed to understand the pathophysiology.