Apparatus for aspirating a volume of liquid contained in a sealed tube having a puncturable stopper mounted at one end thereof, said apparatus comprising (a) a frame; (b) a first drive motor supported by said frame and adapted, in response to having a first electrical current applied thereto, to selectively and incrementally advance a linear lead screw along a predetermined path generally towards or away from said puncturable stopper on said tube, said predetermined path being substantially parallel to the central longitudinal axis of said tube; (c) a linear guide rail slidably mounted on said frame and operatively coupled to said linear lead screw to guide the movement of said linear lead screw along said predetermined path and to move along a path parallel to said predetermined path; (d) a tube detector/stripper member mounted on a housing connecting said linear guide rail with said lead screw, said tube detector/stripper member being adapted to engage the top of a puncturable stopper mounted at one end of a tube as said linear lead screw is advanced along said predetermined path towards said puncturable stopper, whereby said tube detector/stripper member detects that a tube is in a position to have liquid aspirated therefrom; (e) a second drive motor supported by said linear lead screw and being adapted, in response to having a second current applied thereto, to selectively and incrementally move in either of opposite directions along the surface of said linear lead screw, towards or away from said puncturable stopper; and (f) an aspiration probe rigidly connected with said second drive motor, said aspiration probe being aligned with said central longitudinal axis of said tube when said tube detector/stripper member is in contact with a puncturable stopper, said aspiration probe being adapted to puncture said puncturable stopper and thereby move to a liquid-aspiration position within the interior of said tube as said second drive motor moves along the surface of said linear lead screw towards said puncturable stopper. (a) a frame; (b) a first drive motor supported by said frame and adapted, in response to having a first electrical current applied thereto, to selectively and incrementally advance a linear lead screw along a predetermined path generally towards or away from said puncturable stopper on said tube, said predetermined path being substantially parallel to the central longitudinal axis of said tube; (c) a linear guide rail slidably mounted on said frame and operatively coupled to said linear lead screw to guide the movement of said linear lead screw along said predetermined path and to move along a path parallel to said predetermined path; (d) a tube detector/stripper member mounted on a housing connecting said linear guide rail with said lead screw, said tube detector/stripper member being adapted to engage the top of a puncturable stopper mounted at one end of a tube as said linear lead screw is advanced along said predetermined path towards said puncturable stopper, whereby said tube detector/stripper member detects that a tube is in a position to have liquid aspirated therefrom; (e) a second drive motor supported by said linear lead screw and being adapted, in response to having a second current applied thereto, to selectively and incrementally move in either of opposite directions along the surface of said linear lead screw, towards or away from said puncturable stopper; and (f) an aspiration probe rigidly connected with said second drive motor, said aspiration probe being aligned with said central longitudinal axis of said tube when said tube detector/stripper member is in contact with a puncturable stopper, said aspiration probe being adapted to puncture said puncturable stopper and thereby move to a liquid-aspiration position within the interior of said tube as said second drive motor moves along the surface of said linear lead screw towards said puncturable stopper.