The Copper Tube and Hollow Needle must be combined to make a makeshift syringe. The syringe must be placed in a dead man's corpse's head in the Morgue, to allow blood to flow out of it. While the blood is flowing, the player must utilize this opportunity to inject one's self with the blood, which is a vaccination that allows the player to get through fungi gas-ridden areas with ease.
Once the syringe is placed in the corpse's head and used to inject once, it has no further use and is left there.