A pipette device having a pipette unit (1), a positioning unit (4), a micro-dosing unit (5) and a control device (6). The micro-dosing unit (5) is implemented separately from the pipette unit (1). However, it can be coupled to the pipette unit (1) in a precisely defined relative position. The pipette unit (1) thus has a coupling device (10) and the micro-dosing unit (5) has a corresponding counter-coupling device (11). One of the two devices can be switched. By switching the coupling device (10) and/or the counter-coupling device (11), the micro-dosing unit (5) can be coupled to the pipette unit (1) or decoupled from the pipette unit (1) as desired. If the micro-dosing unit (5) is coupled to the pipette unit (1), it can be moved to different operating positions together with the pipette unit (1).

An electrowetting device comprising a cell comprising a working electrode that is formed of a laminar material having a working surface having a surface roughness R.sub.q of 20 nm or less. A suitable laminar material is HOPG.

An assay cartridge has a base member (26) that defines at least two wells (30, 32, 34, 36, 38), a pipette (108, 110) positionable in at least one of the wells and a cap member (86) arranged to carry the pipette. The cap member can be releasably fastened to the base member. An extension member (28) defines at least one further well (40, 42, 44) and can be fastened to the base member such that the pipette is then positionable in at least one of the wells of the base and in the further well of the extension member.

In one aspect, the present invention provides methods, devices, and systems for ensuring that multiple components of a mixture are fully mixed in a continuous flow microfluidic system while ensuring that mixing between segments flowing through the chip is minimized. In some embodiments, the present invention includes mixing fluids in a droplet maintained at the tip of a pipette before the mixture is introduced to the microfluidic device. In another aspect, the present invention provides a pipette tip having a ratio of an outside diameter to an inside diameter that provides sufficient surface area for a droplet comprising up to the entire volume of the liquid to suspend from the pipette tip intact. In yet another aspect, the present invention provides methods, devices, and systems for delivering a reaction mixture to a microfluidic chip comprising a docking receptacle, an access tube and a reservoir.

Devices, systems and methods for making and handling liquid samples are disclosed.

An assembly for a positive displacement sampling device, the assembly comprising a tip and an ejector, the tip comprising a body, a mobile capillary retention portion connected to the body by a connector, and a lever secured to the mobile portion, such that moving this portion radially inwards, via the connector, leads to the lever moving radially outwards, the ejector being equipped with a locking member which engages with the lever such that, in the top position of the ejector, the locking member assumes a locking position in which it holds the mobile portion in an active capillary retention position by preventing the lever from moving radially outwards and, during the ejection travel, the locking member permits the lever to move radially outwards.

A pipetting system including a positive displacement sampling pipette as well as a capillary-piston assembly, the piston of which has a top end intended to be held by a gripping device equipping the pipette, the device including a plurality of gripping tongs. The system is designed so that, when the capillary is fitted on the pipette tip and the gripping device is remote from the piston upwards, this device can be displaced downwards with its tongs in an open configuration, up to a determined position in which the tongs, arranged around the top end of the piston, automatically switch into a closed configuration in which they provide a holding of the top end of the piston.

A bottom part of a positive-displacement pipetting system), including a body slideably housing a device for gripping a piston belonging to a capillary-piston assembly the capillary of which is adapted to be fitted onto an end-fitting of the body. The system also comprises means for ejecting the capillary-piston assembly arranged externally with respect to the body. The system is constructed so that a relative rotation between the ejection means and the gripping device causes it to pass from an open configuration enabling the piston to be released to a closed configuration enabling said piston to be retained, and/or the reverse.

A cylinder tip mounting head includes: a shaft member; a first cylindrical rod having a cylindrical space, which is mounted to a lower end of the shaft member, which is configured to move in the up-down direction integrally with the shaft member; a stationary second cylindrical rod, which has a housing space for housing the first cylindrical rod so that the first cylindrical rod is movable in the up-down direction, the stationary second cylindrical rod including a syringe mounting portion; and a discharge rod housed in the cylindrical space in the first cylindrical rod, the discharge rod including a plunger mounting portion. The discharge rod is configured to coordinate with the movement of the shaft member in the up-down direction so that the plunger mounted to the discharge rod reciprocates in the tubular passage in the syringe to suck the object into the tubular passage and discharge the sucked object.

Methods of determining or verifying proper operation of a diagnostic device are disclosed. The methods include monitoring, with one or more image capture devices, one or more locations to determine proper aspiration, dispense, and/or overall assay component volume fill of one or more bio-liquid containers. Tip immersion depth and location may be also measured and/or verified. Diagnostic devices and apparatus adapted to carry out the method are described, as are other aspects.