A syringe comprising a syringe barrel 8, at least two chambers 10, 12 arranged within the barrel 8, wherein the volume of each chamber 10, 12 is different and each chamber 10, 12 comprises a first open end and a second closed end, the first open end capable of contact with a plunger 4, 6 and the second closed end comprising an outlet 18, 22 and at least two plungers 4, 6, the first plunger 4 for movement within the first chamber 10 and the second plunger 6 for movement within the second chamber 12. A mixing unit 100 comprising a well 102, 104 with an opening 106, 108 adjacent to a base of the well 102, 104, the opening 106, 108 in fluid communication with a syringe and a channel 110, 112, configured to receive a body of the syringe.
