Abstract: A reusable ligation apparatus includes a suture tying or knot tying instrument and a suture cartridge containing a preformed ligature. The cartridge is releasably attached to the instrument so that after a first ligature is made, the apparatus enables one-handed ligation, and can be quickly reloaded with a second cartridge for making another ligature without delay. The cartridge contains a preformed ligature and the instrument includes an activation system which automatically pulls one end of the preformed ligature through loops formed in the other end to thereby form a completed ligature knot.