Syringe with multi-stage filling and dispensing

A method for sequential delivery of at least two separate fluids from a syringe, including the steps of:

• loading a first fluid into a syringe, the syringe having a hollow body having a proximal end opposite a distal end, a plunger extending into the distal end of the hollow body and adapted to translate linearly within the hollow body, a piston movable within the hollow body and between the plunger and the proximal end of the hollow body, a front port accessing a space within the hollow body between the piston and the proximal end of the hollow body, a rear port accessing a space within the hollow body and on a distal side of the piston when the piston is adjacent to the proximal end of the hollow body, and at least one flow path extending from an input/output tip of the syringe and selectively connectable and disconnectable to the front port and/or rear port;
• said loading a first fluid step including retracting the plunger away from the proximal end while the flow path is connected to the rear port;
• loading a second fluid into the syringe by retracting the plunger away from the proximal end while the flow path is connected to the front port;
• and
• delivering the second fluid followed by the first fluid by pushing the plunger toward the proximal end of the syringe while the flow path is connected to both the front port and the rear port.