This mouse has been anesthetized for blood collection from the saphenous vein. The fur on the hindleg has been removed to increase visibility of the vessel. Lubricating eye ointment is applied to the skin before blood collection to prevent blood wicking into the fur. A lancet is being used to nick the vessel, but a small-gauge needle (25 g) can also be used. Once the vessel is nicked, the blood can be collected using a microcapillary tube.