Intraductal Injection: Delivering Injection Mix into the Ducts of the Mouse Mammary Gland

An intraductal injection is a technique of delivering an injection mix that may contain cancer cells, expression vectors, or a therapeutic agent supplemented with a tracer dye into ducts of the mammary gland.

For this procedure, load a syringe with the injection mix. Next, place an anesthetized mouse ventral side up on a surgical bed. Make an incision on the skin between the inguinal or fifth pair of mammary glands. Carefully separate the skin flap from the parietal peritoneum to visualize the ductal tree.

Using forceps, lift the nipple and carefully cut its exterior part to view the duct opening. Use a tweezer to lift the skin flap's edge, and gently insert the syringe needle into the nipple to deliver the injection mix. Monitor the movement of the tracer dye into the mammary ductal tree. The dye spreads out in the ductal tree without leaking into the stroma, indicating a successful injection.

Wait for a few seconds to avoid spillage, then slowly remove the needle from the injection site. Close the incision with the wound clip. In the following protocol, we will perform intraductal injection to deliver Cre expressing adenovirus into the mouse mammary gland.

Use aseptic techniques