Abstract: A system for centrifugation of samples includes at least one carrier, which is provided with a plurality of elements connected with each other by joints and having each an uptake for receiving a sample to be centrifuged, and a rotor for supporting the carrier, with the elements being arranged, in a centrifuged position of the elements, along a circle having its center lying on the rotational axis of the rotor.

Abstract: A plunger lift pipet for a slip-on pipet tip which includes adjusting mechanism for changing the travel of the plunger, display mechanism for the liquid volume pipetted each time, disengageable coupling mechanism between the adjusting mechanism and the display mechanism for changing a pipet correction factor determining the relation between the travel of the plunger and the indicated liquid volume, the coupling mechanism positively connecting to each other the adjusting mechanism and the display mechanism and switching mechanism for completely disengaging the coupling mechanism and changing the pipet correction factor by setting the adjustment mechanism being provided.

Abstract: The present invention relates to a method for defining an error compensation for the difference between a desired quantity of liquid and the quantity of liquid actually drawn into a disposable pipette tip mounted on a plunger-operated pipette, comprising adjusting arrangement (5,6,36,50) for adjusting the stroke of a plunger (9,10) and an indicator 51 for the desired quantity of liquid, wherein the relation of the stroke of the plunger with respect to the quantity of liquid indicated is defined by a plunger-correcting factor, the pipette tip comprising an opening communicating with an operating portion to be filled with a desired quantity of liquid, and a mounting opening for disposably connecting to the plunger-operated pipette, wherein a dead volume is defined between the plunger and the opening communicating with operating portion, and to a pipette system comprising a plunger-operated pipette and a pipette tip.

Abstract: A pipetting apparatus comprising a case and a receptacle formed therein, a pipette tip having a tube-like tip portion with a tip opening for fluid flow from the outside to the inside and vice versa and a deformable portion which is assembled with the tip portion to a unit, the pipette tip being placed in the receptacle with its tip portion projecting outwardly and the pipette tip being detachably connected with the case, an actuating device and an adjusting device coupled thereto which rests against the outside of the deformable portion to press or release the deformable portion and a work volume provided therein which is opened towards the tip opening according to an acuation of the actuating device, whereby the inner width of the undeformed deformable portion exceeds the inner width of the tip opening and that the adjusting device deforms the deformable portion about the whole deformation range of the work volume principally in transverse direction.

Abstract: A mechanism for locking a cover to a housing of medium and high speed laboratory centrifuges. The locking mechanism includes an axially moveable locking member which has at least one locking portion adapted to be moved in locking engagement with a locking hole of the cover. The axially moveable locking member is rotatably mounted in the housing and connected with a rotary drive. An advancing mechanism transforms the rotary movement of the locking member into an advancing movement thereof. Preferably said advancing mechanism includes a threaded portion provided on the locking member and in engagement with a projection provided on the housing. The locking member has a portion of reduced cross section which may pass through a slot into the locking hole when the cover is moved to its closed position.

Abstract: An evacuating apparatus for applying suction to the underside of a microtitration diaphragm plate including a plurality of diaphragm receptacles each having an open top and a diaphragm bottom, the evacuating apparatus including a housing defining an evacuation chamber having an aperture provided in a top wall of said chamber and having associated therewith peripheral gasket means for supporting a rim of said microtitration diaphragm plate, and further comprising a carrier including support means for supporting a microtitration recipient plate including a plurality of closed bottom receptacles each having an open top and a closed bottom, said carrier being adapted to be displaced between an access position wherein said recipient plate may be positioned onto or removed from said support means, and a loading position wherein said recipient plate is disposed within said chamber below said diaphragm plate so that said diaphragm receptacles of said diaphragm plate vertically register with said closed bottom recepta

Abstract: For a microinjection of liquids or suspensions of substances into living cells, a stage and a cannula, which is movably mounted and extends at an oblique angle relative to the stage, are arranged to be movable relative to each other, the cells being contained in a culture vessel on the stage, the tip of the cannula constitutes a pointer and is moved in a plane z.sub.1, which is parallel to the stage and is disposed above the cells on the stage, the tip is moved to a position exactly over the location which is desired for an injection and thereafter, the cannula is moved away from the selected cell in the direction of the projection of the cannula on the plane and over a distance which depends on the angle between the cannula and the plane, the cannula is thus moved to a setback position, in which the axis of the cannula extends through the desired location, the cannula is then axially moved to puncture the cell and is subsequently reversed.

Abstract: A pipetting device is provided at its top with an actuating element, which is depressible against spring action and which is connected to a piston, which is movable in a cylinder to move an air volume. The cylinder communicates with an opening in a particularly conical pipette connector, on which a pipette tip which open-topped and open-bottomed is adapted to be slidably fitted. The pipettable volume is adapted to be adjusted by a rotation of the actuating element. The actuating element consists of a knob, which is axially movable to establish and separate a detent element joint between a screw and a nut which is fixed in the housing. By a rotation of the actuating knob the screw can be rotated in said nut to impart an axial movement to a piston rod, which is connected to the piston so that the latter is infinitely adjustable in known manner. At least one of the detent elements which constitute the detent element joint comprises teeth which are spaced around the center line of the pipetting device.

Abstract: A pipetting device comprises a retaining cone for holding a slip-on pipette tip and a piston chamber, which communicates with a passage of the retaining cone and contains a reciprocable piston, which acts on the pipette tip that has been fitted on the retaining cone. A filter is provided in the assembly and consists of an aerosol-retaining filter that is detachably mounted in a region which includes the lower end of the pipetting device (1), including the retaining cone (8), as well as the upper end portion of the pipette tip (10) below the retaining cone. The filter may be designed in various ways and may have a progressive filter action. The filter may be arranged in the lower end portion of the retaining cone (8) or in the pipette tip (10) or in an interposed member.

Abstract: For the taking of liquid from large-volume, deep vessels by means of sucking vessels having short suction elements, a metered stand-by volume of liquid, which is accessible from above, is sucked from a volume of liquid of changing depth in the deep vessel and a defined sample of liquid is sucked from said stand-by volume at the same time. The auxiliary sucking device comprises a tube, which is adapted to be introduced into the deep vessel, and a check valve, which prevents a flow to the open bottom end of the tube. The tube is mounted on a bowl, which is adapted to be placed on the mouth of the deep vessel. The bowl preferably constitutes a portion of a housing in which the open top end of the tube is disposed close to the top wall of the housing. The top portion of the bowl contains an entrance opening, which is disposed above the stand-by volume of liquid, at least part of which is contained in the bowl.

Abstract: A fittable pipette tip consists of a vessel which is designed to fit a particularly conical fitting head of a pipette and which may be conical and has a fitting top opening and a bottom opening for receiving and discharging a pipette. A sealing portion with which the pipette tip is adapted to contact the fitting head is spaced from the top end of the pipette tip and is formed with a smooth inside seating surface and has a smaller wall thickness than other portions of the pipette tip so that the sealing portion of the pipette tip is yieldable for adaptation to the fitting head. The pipette tip is reduced in wall thickness at least in the sealing portion by a provision of recesses in the outside and inside surfaces of the wall of the pipette tip.

Abstract: A fillable sample taking element for handling a liquid sample has a conical end portion which defines an intake and discharge opening, which is adapted to be sealed by a conical valve member, which is provided with an actuating rod, which protrudes outwardly through the intake opening and is bare relative to said intake opening. The valve constitutes a gravity valve having a valve member (8) which is disposed in the interior of the sample taking element (3) in the tapering portion (13) thereof which is disposed above and tapers from the intake opening (6). The valve seat for that valve member has a surface which faces away from the intake and discharge opening. The outwardly protruding actuating rod (10) serves to unseat the valve member. The valve will be closed when the sample taking element is arranged with the intake and discharge opening at the bottom and/or under the action of an internal pressure in the sample taking element.

Abstract: A rotor for a centrifuge comprises a bottom part and a top part. The top part is formed with openings for receiving test tubes in rim engagement. The bottom part has an upwardly deformed outer rim, which constitutes a collecting trough. The test tubes are particularly indirectly inserted into the openings (3 to 5) and are biased by spring means (21), which engage the particularly indirectly inserted test tubes from the inside and urges them outwardly against a frustoconical wall (10) of the top part. For an indirect insertion of the test tubes, they may be inserted into guide inserts (6, 7) which consist of cylindrical bushings and are urged outwardly.