Plunger for reducing the dead volume of a syringe

An application vessel comprising:

• a longitudinal portion;
• a piston with a piston rod, piston the piston being guided in a movable manner in the longitudinal portion, and which piston closes the application vessel at one end and which is movable by means of the piston rod;
• a connection for fitting an injection needle at another end of the application vessel, wherein the piston, for reducing a dead volume, is displaceable beyond a distal end of the connection, wherein the connection is configured as a Luer- or Luer-lock-connection, wherein a dead space extends, when the injection needle is fitted on the connection, with an axial dead space length and with a radial dead space internal cross-section in a distal direction from the distal end of the connection, wherein the piston is displaceable into the dead space, wherein the dead space internal cross-section is greater than an internal cross-section of the longitudinal portion, which continues on the distal side up into the connection, wherein at least a part of the piston is configured to be pliant-elastic at least transversely to a piston displacement direction such that the part of the piston widens in the dead space radially into the dead space internal cross-section.