Reagent cartridge opening module for opening reagent vessels (110, 111) with a screw-on reagent vessel lid, comprising - a carrier, configured to rotate around an axis of the reagent cartridge opening module, having at its lower end a catch element which is configured to lock securely against rotation into a catch element of the reagent vessel lid, so that a rotational movement of the catch element causes a rotational movement of the reagent vessel lid, the carrier being arranged concentrically about a centring unit, - the centring unit which is essentially guided via a guide inside the carrier, and which has, at its lower end, a snap-in element (5, 51, 54, 64, 69, 70) which can engage in a snap-in element of the reagent vessel lid, providing a snap-fit connection between the reagent cartridge opening module and the reagent vessel lid, so that the reagent vessel lid clings to the snap-in element (5, 51, 54, 64, 69, 70) and at least partially follows the movement of the snap-in element (5, 51, 54, 64, 69, 70), wherein the snap-fit connection is realized separately from the rotationally secure connection of the reagent vessel lid to the carrier, - a drive unit configured to move the centring unit, and with it the carrier in the Z direction along the axis which is perpendicular to the plane of the rotational movement of the catch element, characterized in that the centring unit is connected to the carrier via springs (8, 9) mounted via abutments (11, 7) of the centring unit and of the carrier, respectively, such that the centring unit can move onwards inside the carrier in the Z direction when the movement of the carrier towards the reagent vessel (110, 111) is stopped by the reagent vessel lid or when the carrier, being moved away from the reagent vessel (110, 111), abuts against a holding device. - a carrier, configured to rotate around an axis of the reagent cartridge opening module, having at its lower end a catch element which is configured to lock securely against rotation into a catch element of the reagent vessel lid, so that a rotational movement of the catch element causes a rotational movement of the reagent vessel lid, the carrier being arranged concentrically about a centring unit, - the centring unit which is essentially guided via a guide inside the carrier, and which has, at its lower end, a snap-in element (5, 51, 54, 64, 69, 70) which can engage in a snap-in element of the reagent vessel lid, providing a snap-fit connection between the reagent cartridge opening module and the reagent vessel lid, so that the reagent vessel lid clings to the snap-in element (5, 51, 54, 64, 69, 70) and at least partially follows the movement of the snap-in element (5, 51, 54, 64, 69, 70), wherein the snap-fit connection is realized separately from the rotationally secure connection of the reagent vessel lid to the carrier, - a drive unit configured to move the centring unit, and with it the carrier in the Z direction along the axis which is perpendicular to the plane of the rotational movement of the catch element, characterized in that the centring unit is connected to the carrier via springs (8, 9) mounted via abutments (11, 7) of the centring unit and of the carrier, respectively, such that the centring unit can move onwards inside the carrier in the Z direction when the movement of the carrier towards the reagent vessel (110, 111) is stopped by the reagent vessel lid or when the carrier, being moved away from the reagent vessel (110, 111), abuts against a holding device.