Patent ID: 8268263

Claim:
A self dispensing reagent cartridge compromising a vessel having an inner wall surface with opposite end portions, (a) one end portion of the vessel accommodating a movable piston having a compression surface, (b) a puncturable septum at the opposite end portion of the vessel, (c) a vessel space of variable volume defined by the inner wall surface of the vessel between the septum and the position of the compression surface of the piston relative to the puncturable septum, the vessel space containing a reagent; (d) a hollow needle member on a rigid needle support flange, the needle support flange positioned between the puncturable septum of the vessel and a cuvette, the needle support engageable to an upper end of the cuvette, and said needle member having a septum puncturing end that is normally spaced from and directed towards the puncturable septum and a blunt outlet end aligned with an inside space of the cuvette, wherein the needle support flange extends radially outward from a portion of the needle member between the septum puncturing end and the blunt outlet end, wherein the hollow needle member is operational to transfer the reagent from the vessel to the cuvette, (e) said vessel and said needle member with support being relatively movable toward each other to locate the septum puncturing end of said needle member in a septum puncturing position, to enable a predetermined amount of the reagent in the vessel space to be transferred outwardly of the vessel though the hollow needle member, corresponding to a change of position of the compression surface of the piston relative to the septum after the septum puncturing end of said needle is located in the septum puncturing position and, (f) said vessel and needle member with needle support flange being relatively movable away from each other to withdraw the puncturing end of the needle from the septum puncturing position to enable the septum to self seal.