A syringe, comprising: (a) an elongate hollow body having a first open end , an inside wall, a second open end, and an annular raised lip on said inside wall; (b) a syringe plunger positioned in said hollow body through said second open end, said plunger comprising: (i) an elongate shaft having a longitudinal axis, an upper end portion and a lower end portion; (ii) a seal connected to said lower end portion; (iii) a flange connected to said upper end portion; and (iv) a first set of detents formed on said elongate shaft in a linear and uniformly spaced pattern thereon aligned with said longitudinal axis, with each member of said first set of detents configured to sequentially and releasably engage said lip when said plunger is withdrawn from or depressed into said hollow body ; said syringe having a total volume, with said first set of detents configured to divide said total volume into a plurality of separate subvolumes, characterized in that each of said first set of detents comprises a flexible leaf; and wherein the flexible leaf comprises a living hinge connecting the flexible leaf to the elongate shaft . (a) an elongate hollow body having a first open end , an inside wall, a second open end, and an annular raised lip on said inside wall; (b) a syringe plunger positioned in said hollow body through said second open end, said plunger comprising: (i) an elongate shaft having a longitudinal axis, an upper end portion and a lower end portion; (ii) a seal connected to said lower end portion; (iii) a flange connected to said upper end portion; and (iv) a first set of detents formed on said elongate shaft in a linear and uniformly spaced pattern thereon aligned with said longitudinal axis, with each member of said first set of detents configured to sequentially and releasably engage said lip when said plunger is withdrawn from or depressed into said hollow body ; said syringe having a total volume, with said first set of detents configured to divide said total volume into a plurality of separate subvolumes, characterized in that each of said first set of detents comprises a flexible leaf; and wherein the flexible leaf comprises a living hinge connecting the flexible leaf to the elongate shaft . (i) an elongate shaft having a longitudinal axis, an upper end portion and a lower end portion; (ii) a seal connected to said lower end portion; (iii) a flange connected to said upper end portion; and (iv) a first set of detents formed on said elongate shaft in a linear and uniformly spaced pattern thereon aligned with said longitudinal axis, with each member of said first set of detents configured to sequentially and releasably engage said lip when said plunger is withdrawn from or depressed into said hollow body ; said syringe having a total volume, with said first set of detents configured to divide said total volume into a plurality of separate subvolumes, characterized in that each of said first set of detents comprises a flexible leaf; and wherein the flexible leaf comprises a living hinge connecting the flexible leaf to the elongate shaft . with each member of said first set of detents configured to sequentially and releasably engage said lip when said plunger is withdrawn from or depressed into said hollow body ; said syringe having a total volume, with said first set of detents configured to divide said total volume into a plurality of separate subvolumes, characterized in that each of said first set of detents comprises a flexible leaf; and wherein the flexible leaf comprises a living hinge connecting the flexible leaf to the elongate shaft . <EOS>