A sterile transfer device (2) for fluids, be they liquids or gases. It comprises a body (4) having a bore (10) formed through at least a portion of its interior, the body (4) having a first end (6) containing a face designed to be attached to an upstream component (54；72). Contained within the bore is a plunger (18；70；108), the plunger having a first end and being movable within the bore, wherein the first end of the plunger (18；70；108), when in a closed position, is in alignment with the face of the first end (6) of the body (4), which combined form a steamable surface (46；104) and a sterile barrier against the environment to the rest of the interior of the body (4) and the plunger (18；70；108). A cam slot (36) is formed in the body (4), and a cam (32) is provided on the plunger (18；70；108), wherein the cam (32) rides in the cam slot (36) such that a rearward and forward movement and a rotation of the plunger (18；70；108) within the bore (10) is defined.
