This article details the procedure for harvesting inguinal lymph nodes from euthanized mice. The inguinal lymph nodes play a crucial role in filtering lymphatic fluid and mounting immune responses.
In mice, the inguinal lymph nodes are small, ovoid-shaped organs of the lymphatic network located in the inguinal region — the area between the thighs and the lower abdomen.
The inguinal lymph nodes receive lymphatic drainage from the mouse's lower extremities. It filters the lymph to identify pathogens and cancerous cells to mount an immune response.
To harvest a murine inguinal draining lymph node, prepare a euthanized mouse in the supine position and secure it on an acrylic stage. Apply mineral oil on the inguinal region to avoid fur interference during the incision.
Make a longitudinal incision along the abdominal area, from the pubis to the xiphoid process — the lower end of the sternum, exposing the inguinal region.
Next, dissociate the skin from the abdominal muscles for efficient extraction. Create small horizontal incisions at the top and bottom of the longitudinal incision, creating a skin flap.
Retract the skin flap, and secure it to access the underlying tissues, including the inguinal lymph node. Pierce through connective tissue to access the lymphatic system and extract the inguinal lymph node from the system.
The harvested bi-lobular inguinal lymph node is ready for future experiments.
For inguinal draining lymph node harvest, apply mineral oil to the abdominal skin. Use standard microsurgery scissors and microsurgery curved forceps to make a midline skin incision in the abdomen from the pubis to the xiphoid process, and dissociate the abdominal musculature from the skin.
Make horizontal skin incisions at the top and bottom of the vertical incision line to create skin flaps on the side of injection, and retract the skin to visualize the lymph node. Secure the skin flap to the acrylic plate, and use the forceps to remove the translucid, usually bilobular, spherical inguinal draining lymph node.