Abstract: The present disclosure provides better aspiration and dispensing of fluids by an innovative mechanism by (i) offsetting the diameter of a bottom tube with a narrower top piston when the two are moved together in the same chamber to give extremely fine resolution, thereby eliminating the need for any skinny or filamentous piston, (ii) letting the bottom tube move in the chamber alone without offset to give high flow, (iii) an at-the-ready space between the tube and piston in the chamber to permit contact-free blowoff, including viscous samples, and (iv) a frame, adjustable knob and readable volume gage that let the mechanism operate as a handheld pipettor apparatus for various volumes.

Abstract: A pipette for use with a pipette tip or syringe including a piston positioned within a cylinder comprises a pipette housing extending between an upper end and a lower end. Two parallel rods are positioned in the pipette housing, wherein one of the two parallel rods is coupled to a lifting rod. An operating element is configured to protrude outwardly from the pipette housing and be displaced relative to the pipette housing. A gear mechanism is arranged in the pipette housing and comprises a drive comprising a moveable input member and configured to be driven by the operating element, and an output comprising at least one moveable output member and configured to drive the two parallel rods. Successive displacements of the input member by the operating element are configured to alternately displace one of the two parallel rods and then another of the two parallel rods by the output member.

Abstract: The present disclosure provides better aspiration and dispensing of liquids by an innovative mechanism by (i) offsetting the diameter of a bottom tube with a narrower and tapered top piston when the two are moved together in the same chamber to give extremely fine resolution, thereby eliminating the need for any skinny or filamentous piston, (ii) using thick walled compliant O-rings to seal against the different diameters of the tapered piston to given an additional order of magnitude range of resolution, (iii) letting the bottom tube move in the chamber alone without offset to give high flow, and (iv) an at-the-ready space between the tube and piston in the chamber to permit contact-free blowoff, including viscous samples.

Abstract: An apparatus for washing an array plate includes one or more dispensers and one or more aspirators that are distinct from the one or more dispensers. A respective dispenser of the one or more dispensers is configured to dispense a first liquid on the array plate, and a respective aspirator of the one or more aspirators is configured to aspirate liquid on the array plate. A method for washing particles is also disclosed.

Abstract: A cartridge reader is configured to carry out a diagnostic test on a fluid sample contained within a fluidic cartridge. The cartridge comprises first, second and third collapsible blisters containing at least one reagent for use in the diagnostic test. The cartridge reader comprises an upper clamp, occupying a fixed position relative to the reader and a lower clamp, movable relative to the upper clamp, and wherein the upper clamp and the lower clamp are configured to receive and hold a fluidic cartridge therebetween. First, second and third blister actuators are mounted on the upper clamp, for aligning with first, second and third collapsible blisters of a fluidic cartridge inserted into the reader.

Abstract: In order for the handling of a pipette to be improved, the pipettes (1) according to the invention and a method according to the invention for setting a volume of a pipette to be pipetted are proposed. In the case of the pipette (1) it is provided that the activation element (7) for activating the ejection mechanism (6) for ejecting a pipette tip forms a conduit (9) for the pipetting button (3). On account thereof, an activation face (10) of the activation element (7) is enlarged in such a manner that the handling of the ejection mechanism (6) of the pipette (1) is in particular simplified and is particularly comfortable. It is furthermore also proposed that the activation element (7) is coupled to the volume adjustment mechanism (11) of the pipette, and the adjustment of the volume to be pipetted by the pipette (1) is performed with the aid of a movement of the activation element (7)(FIG. 4).

Abstract: A pipette calibration and volume offset mechanism. The calibration and volume offset mechanism is provided to facilitate user selectable calibration or volume offset operations of a pipette to which the calibration and volume offset mechanism is installed, through axial displacement of a threaded element that effectively moves the home position of the pipette. An offset counter of the calibration and volume offset mechanism is rotationally coupled to the threaded element during a volume offset operation to indicate offset magnitude, but decoupled from threaded element during a calibration or recalibration operation.

Abstract: A dosing syringe comprising a barrel and a piston is provided. The piston is slidably receivable in the barrel and can move within the barrel from a maximum inserted position to a withdrawn position to draw a dose of a product into the barrel. The syringe comprises means for pre-setting the withdrawn position, which defines a maximum dose which can be drawn into the barrel.

Abstract: A dispensing cylinder capable of performing a dispensing treatment for both minute and large amounts of liquid includes: a cylinder having a cavity; a nozzle provided at one end of the cylinder, having a through hole in fluid communication with the cavity and extending in an axial direction of the cavity, and a plunger slidable in the cavity in the axial direction. The cavity has a large diameter region having a large inner peripheral surface and a small diameter region having a second inner peripheral surface. The plunger has a thick shaft portion slidable in the large diameter region and a thin shaft portion protruding from a distal end of the thick shaft portion in the axial direction and slidable in the small diameter region.

Abstract: This disclosure concerns a pipette system with an interchangeable volume counter. Aspects of the pipette body design and external dimensions allow various functional features of the pipette system, and, thus, various interior adjustment part designs and dimensions, to be accommodated in a single pipette body design. A three-digit volume counter, a four-digit volume counter, or an electronic counter can be installed in the same pipette body design.

Abstract: The manual dosing device (1) comprises the main body (3) that can be screwed to the fluid discharge unit (4), the detent connection (10) being provided alongside the screw connection (6) for removably connecting the main body (3) to the fluid discharge unit (4), which detent connection is locked by connecting the main body (3) and the fluid discharge unit (4) together (cf. FIG. 5).

Abstract: Embodiments of the preset invention provide a fluid collector configured to releasably engage with an injector. The fluid collector comprises a fluid container configured to have a centrally extended conical projection containing a detachable needle holder at a proximal end of said conical projection to hold a detachable hypodermic needle, a piston assembly having a piston flange provided with a conical cavity at center of said piston assembly at a distal end of said piston assembly to couple said plunger shaft of said injector and a container cover being internally provided with a concave diaphragm having a central hole to allow entry of said detachable hypodermic needle along with a detachable needle hub.

Abstract: Mechanical pipette with adjustable volume value of aspirated liquid is built of a handle (1) and a nozzle (3) and coupled with them: an ejection mechanism of a pipette exchangeable tip (8), a drawing up and discharging mechanism with a plunger (33) mounted in said pipette nozzle (3), a plunger working stroke adjustment mechanism, a manually actuated lock mechanism of a drive assembly of an adjustment screw of the plunger working stroke, a mechanical counter, a drive mechanism of a mechanical counter and a calibration mechanism for correction of the pipette accuracy deviation. The calibration mechanism comprises, mounted in the mechanical counter, releasable coupling means for complete disengagement of a revolvers assembly from the mechanical counter drive mechanism in CALIBRATION MODE, further, engaged with them, changeover means for changing over the pipette into CALIBRATION MODE and resetting means of the indication of the liquid volume value on the counter in CALIBRATION MODE.

Abstract: To provide an electric pipette in which the impact resistance against the dropping of the electric pipette is elevated, the external breakage of the device and the damage of operation performances are reduced, and the discharging performance of the device is maintained and ensured. An electric pipette 100 including a main casing 1, an operation switch 14, a hand grip 15, a display-operation section 9, a release switch 12 and a finger rest 16, in which at least one shock absorber 201 to 206 disposed on at least one apex of at least one line among a line LF, a line LB, a line LL, a line LR and a line LU, which are prepared by drawing lines between two or more projecting sites in each of a front surface 100F, a back surface 100B, a left side surface 100L, a right side surface 100R and an upper surface 100U.

Abstract: An electronic pipette comprising a piston actuated in a cylinder by a motor, a control system for carrying out pipette operations, and a user interface for operating the pipette, which user interface comprises a display, wherein the main menu of the user interface comprises a user defined shortcut to a specific pipetting application.

Abstract: A manually actuated sampling pipette including a piston designed to undergo a dispensing movement during which a first elastic return is loaded, followed by a purge movement during which a second elastic return is loaded, and comprising an electronic device that receives a switching signal notifying passage of the piston through a predetermined position along its dispensing distance or its purge distance, position in which the elastic returns have a predetermined deformation. The pipette also includes a switch that outputs the signal to the electronic device. Furthermore, an elastic support is included which is capable of deforming under the effect of the axial pressure applied by the operator, and the pipette is designed such that deformation of the support, generating switching, is caused when the intensity of the axial pressure is greater than the intensity bringing the elastic returns to their predetermined strain level.

Abstract: For use in an electronic pipette, a brake mechanism which is used for abruptly stopping the movement of the actuator that moves the plunger, which mechanism comprises a rotatable, essentially circular rotor that is at its periphery provided with brake notches arranged at regular intervals, and a brake actuator comprising a motion inducing means, a brake member (1) to which a brake cam (11a), compatible with the brake notches is connected, a mediation mechanism for transmission of the movement of the motion inducing means to the brake member, the brake member comprising, connected to the motion inducing means, a turnable member (2) that is arranged to act with the brake member such that the movement of the turnable member can be accelerated before it essentially effects the movement of the brake member.

Abstract: The present invention relates to a pipette having: a rod-shaped handle body in which a drive unit is arranged for a displacement unit having an operating element in the top end, and having a seat for a pipette tip or syringe in the bottom end, wherein the handle body has a front grip surface that is approximately straight in the bottom part of the handle body in a vertical sectional plane through the handle body, and curves across the handle body toward a thumb rest in the top part of the handle body above the area that comes into contact with the surface of the hand, and the operating element actuatable with the thumb is arranged in the thumb rest.

Abstract: A pipette with a rod-shaped casing, a seat, a displacement equipment, comprising a displacement chamber with a relocatable limit, a connection channel, a drive equipment for relocating the relocatable limit of the displacement chamber, coupled to the relocatable limit and having an axially relocatable lifting rod, an upper stop body, a lower stop body and a stop element on the circumference of the lifting rod for limiting the stroke of the lifting rod, an overstroke spring, a stationary screw element, and with a screw element that is relocatable in the casing, a toothing, running along a helical line with the same pitch as that of the thread of the relocatable screw element and having teeth on the upper edge of the relocatable screw element that are directed in the direction of the instantaneous axis of the relocatable screw element, a toothed driving wheel, and means for rotating the toothed driving wheel.

Abstract: A device for receiving and dispensing liquids has a plurality of piston-cylinder units (1, 1?, 1?) which are respectively arranged on a piston plate (2) and a cylinder plate (3). The liquid is received and dispensed by displacing the pistons (1?) in the cylinders (1?) by changing the distance between the plates (2, 3), perpendicularly to the plate planes, by means of a drive mechanism (6) and a plate guiding system. The volume can be determined by an upper abutment (4) and a lower abutment (5), at least one of said abutments being regulatable by a regulating means (8). The device is suitable for handling precise volumes of a larger number of piston-cylinder units (1, 1?, 1?) in a technically simple manner.

Abstract: There is provided a pipette device capable of adjusting a collection amount in a short time. A pipette device 1 adjusting a volume of a cylinder portion “a” by the axial-direction movement of a plunger 3 caused by the rotation of a push rod 5 includes a speed increasing mechanism 35 provided between a pipette main body 2 and the push rod 5 and increasing a speed of input rotation to transmit the input rotation with the increased speed to the push rod 5.

Abstract: A volume adjustable pipette, comprising a plunger mounted for movement in a housing to and from a stop to aspirate a fluid into and dispense the fluid from a tip extending from the housing. The movement of the plunger is damped to reduce sudden plunger movements. An axially moveable volume setting member in the housing defines the stop and a volume setting for the pipette and is axially moveable by a user turnable volume setting member. Turning of the volume adjusting member also controls a coarse volume setting means and a fine volume setting means, the course volume setting means being responsive to a relatively small turning of the volume adjusting member for moving the volume setting member a relatively large axial distance and the fine volume setting means being responsive to a relatively large turning of the volume adjusting member for moving the volume setting member a relatively small axial distance.

Abstract: Pipette with adjustable volume of aspirated liquid built of a handle (1) and of a nozzle (3) and of coupled with them: an exchangeable pipette tip ejection mechanism, a drawing up and discharging mechanism with a plunger (12) arranged in said pipette nozzle (3), a plunger working stroke adjustment mechanism with at least one driving member (16), a manually actuated lock mechanism locking a drive assembly of an adjustment screw of a plunger working stroke, an engaging mechanism which engages said plunger working stroke adjustment mechanism with a counter (14) of an aspirated liquid volume by said pipette, a calibration mechanism for a change of a pipette calibration coefficient, whereas said driving member (16) of said drive assembly of said adjustment screw of the plunger working stroke is accessible from outside through at least one window (38) in a wall of said handle (1), said pipette is characterized in that said lock mechanism of said drive assembly of said adjustment screw of the plunger working stroke

Abstract: The present invention is related to a pipetting device with a throw-off system for detachably connecting with at least one pipette tip, at least one displacement device, a driving device for driving a displacement member of the displacement device and an adjustment device with a lead screw nut and a lead screw for adjusting the metering volume.

Abstract: A plunger stroke pipette for replaceable pipette points with a seat for the detachable mounting of a pipette point, a plunger, a cylinder in which the plunger is movably arranged, a connection channel connecting the cylinder with an opening in the seat, a driving equipment, coupled to the plunger for displacing the plunger in the cylinder, an upper stopper and a lower stopper and at least one counter-stopper of the driving equipment and/or the plunger for limiting the stroke of the plunger, a holder, holding the lower stopper, an overstroke spring between the upper stopper and the holder, an adjustment equipment for adjusting the position of the holder with respect to the cylinder, and an indicating equipment for indicating the position of the holder.

Abstract: An electronic metering apparatus for metering liquids with a drive with an electric motor, at least one displacer device with a displacer element, which is connected and/or connectable to the drive, an electric mode key and an electric parameter key for changeover between different menus, a pair of electric control keys, arranged next to each other, for navigation in the menus, setting of parameters and controlling the dislocation of the displacer element, wherein the two control keys control the navigation in the menus, the setting of parameters and the dislocation of the displacer element in different directions, an electronic display device for displaying menus and parameters, an electric control unit, which is connected to the electric motor, the electric mode key, the electric parameter key, the electric control keys and the electric display device, and which controls the display of menus and parameters by the display device as well as the dislocation of the displacer element corresponding to the actuati

Abstract: The invention provides hand-held pipettor in accordance with an embodiment that includes a piston that is received in one end of a cylinder, a pipettor tip that is removably secured to an opposite end of said cylinder, a manually driven unit that reciprocates the piston through a selected stroke to aspirate fluid into and to expel the thus aspirated fluid from the pipettor tip, a mechanism including a stepper motor responsive to control signals for adjusting a range of the stroke, and a voice recognition system that decodes verbal commands and outputs the result to a central processing unit, which in turn generates the control signals.

Abstract: The invention provides extraction columns for the purification of an analyte (e.g., a biological macromolecule, such as a peptide, protein or nucleic acid) from a sample solution, as well as methods for making and using such columns. The columns typically include a bed of extraction media positioned in the column between two frits. In some embodiments, the extraction columns employ modified pipette tips as column bodies. In some embodiments, the method involves adjusting the head pressure of the column during the process, or otherwise controlling or regulating the head pressure.

Abstract: A volume adjustable pipette, comprising a plunger mounted for movement in a housing to and from a stop to aspirate a fluid into and dispense the fluid from a tip extending from the housing. The movement of the plunger is damped to reduce sudden plunger movements. An axially moveable volume setting member in the housing defines the stop and a volume setting for the pipette and is axially moveable by a user turnable volume setting member. Turning of the volume adjusting member also controls a coarse volume setting means and a fine volume setting means, the course volume setting means being responsive to a relatively small turning of the volume adjusting member for moving the volume setting member a relatively large axial distance and the fine volume setting means being responsive to a relatively large turning of the volume adjusting member for moving the volume setting member a relatively small axial distance.

Abstract: An electronic metering apparatus for metering liquids with a drive, at least one displacer device with a displacer chamber and a displacer element arranged therein, which is connected to the drive, at least one holding device for a pipette point, which has a passage channel which is connected with the displacer chamber, a data memory with memory locations for different calibration data concerning different pipette points and/or different liquids and/or different usage conditions, an electric selection device for selecting calibration data, an electric control unit, which is connected to the electric selection device, the data memory, and to the electric drive motor of the drive and/or an electric display device, and which controls the movement of the displacer element by means of the electric motor and/or the display of the metering volume through the display device with recourse to the calibration data from the data memory, selected with the aid of the selection device, and an electric power supply.

Abstract: The present invention is related to a pipetting device with means for detachably connecting with at least one pipette tip, at least one displacement device, a driving device for driving a displacement member of the displacement device and an adjustment device with a lead screw nut and a lead screw for adjusting the metering volume.

Abstract: The present invention provides systems for isolating toxins and collecting an eluate from a sampling column for subsequent testing and to methods of extracting and collecting an eluate using the same systems. Preferably, the systems comprise a sample holder such as an immuno-affinity column for holding the sample and a self-contained fluid delivery system that can deliver liquid, e.g., reagents, and gaseous fluids, e.g., compressed air. More preferably, the fluid control system of the fluid delivery system provides some amount of pressurized gas continuously to the headspace of the column even when a fluid is not being forced through the resin gel in the column.

Abstract: The invention relates to an electric pipette (1) comprising a body (2), a tip part (4), a hook part (5), a push-button part (6) and a display part (7), said body (1) having a vertical axis (3) and at least one of the parts selected from the group consisting of the hook part (5), the push-button part (6) and the display part (7) is rotatable about the vertical axis (3) of the electric pipette (1) correspondingly by an angle ?1, ?2 or ?3.

Abstract: The object of this invention is a method for attaching a pipette tip and an apparatus for such method. The method comprises the following steps: opening the interlocking which attaches the replaceable part with the help of electronically controlled interlocking mechanism for detaching or receiving the replaceable part; saving the information of the opening of the interlocking mechanism to the control electronics of the pipette; closing the interlocking which attaches the replaceable part with the help of the electronically controlled interlocking mechanism for attaching the replaceable part; saving the information of the closing of the interlocking mechanism to the control electronics of the pipette; providing the dispensing parameters and/or type and/or size of the replaceable part with the help of a keyboard to the control electronics to ensure the attachment of a desired replaceable part and to achieve pipetting readiness.

Abstract: A hybrid manual-electronic pipette combines a manually driven piston with real-time electronic measurement of liquid volume and piston displacement while compensating for both pipette-specific and pipette model-specific variations. The hybrid nature of the pipette facilitates increased accuracy and improved ease of use, and enables additional functionalities not practicable with traditional manual pipettes.

Abstract: A hybrid manual-electronic pipette combines a manually driven piston with real-time electronic measurement of liquid volume and piston displacement while compensating for both pipette-specific and pipette model-specific variations. The hybrid nature of the pipette facilitates increased accuracy and improved ease of use, and enables additional functionalities not practicable with traditional manual pipettes.

Abstract: A hybrid manual-electronic pipette combines a manually driven piston with real-time electronic measurement of liquid volume and piston displacement while compensating for both pipette-specific and pipette model-specific variations. The hybrid nature of the pipette facilitates increased accuracy and improved ease of use, and enables additional functionalities not practicable with traditional manual pipettes.

Abstract: A pipette includes a tubular body (1) having an internal circumferential threaded portion (1b); a stroke screw (5) provided inside the body (1) and having an external circumferential threaded portion (5c) for thread-engaging said internal circumferential threaded portion (1b); a volume variably setting member (4) disposed to be rotatable together with the stroke screw (5) as one unit and axially slidable relative thereto; a central shaft (7) provided inside said tubular body (1), which is coupled to a plunger (29) and operable to be pushed down; and a first-stage spring (10) interposed between an upper portion of said central shaft (7) and said stroke screw (5), which urges the central shaft (7) upward so that a predetermined portion (7b) thereof urgingly abuts against the stroke screw (5), wherein, by rotating said volume variably setting member (4) as appropriate, the stroke screw (5) is caused to rotate together therewith as one unit relative to the body (1) so that said stroke screw (5) and said central s

Abstract: The invention relates to an electronic pipette comprising a piston actuated by a motor, a control system, a user interface (1, 2) and a display (3). The control system comprises at least two pipetting setting arrays, each comprising at least one setting, such as a calibration setting or a pipetting function setting acting over the entire volume range, which setting can be changed for each array of settings, with the desired setting array being selectable for use each time. This enables the pipette to be readily used for various purposes of use without having to adjust these settings separately.

Abstract: A piston coupling for a micro-liter range liquid dispensing system for connecting a piston to a piston drive shaft generally includes a U-shaped body portion having a U-shaped arm and an annular barrel-shaped bearing seated in the U-shaped body portion and retained by the U-shaped arm. The bearing includes an axial bore for receiving the piston, wherein the annular barrel-shaped bearing is designed for balancing the forces applied to the piston by the piston drive shaft symmetrically about the centerline of the piston.

Abstract: A hand-held pipette includes a piston driven by an actuator assembly contained within a housing having first and second mutually spaced non-adjustable stops. The actuator assembly is subdivided into first and second sections respectively provided with first and second contact surfaces. The actuator assembly is arranged to reciprocate between a rest position at which the first contact surface is in contact with the first stop and the second contact surface is spaced from the second stop by a control distance, and an advanced position at which the second contact surface is in contact with the second stop and the first contact surface is spaced from the first stop, with the stroke of the actuator assembly and the stroke of the piston being equal to the control distance. A motor-driven mechanism is arranged to displace one section of the actuator assembly relative to the other section, resulting in a corresponding change to both the overall length of the actuator assembly and the control distance.

Abstract: The mechanical piston pipette comprises a pipette body, a piston/cylinder assembly, the cylinder being arranged so as to be able to be equipped with a replaceable tip, and a tip ejector device, movable along the cylinder in order to eject a tip from the end of the cylinder. The pipette body accommodates an ejection actuation device and a piston actuation device (3, 4, 7) effecting given longitudinal translational travel between a low limit stop position and a high limit stop position in order to perform the aspiration of an adjustable volume of liquid, with means of modifying said travel, means (4) of adjusting the pipetted volume, means (8e, 8f, 8g) of displaying the pipetted volume and calibration means.

Abstract: A volume adjustable pipette, comprising a plunger mounted for movement in a housing to and from a stop to aspirate a fluid into and dispense the fluid from a tip extending from the housing. An axially moveable volume setting member in the housing defines the stop and a volume setting for the pipette and is axially moveable by a user turnable volume setting member. Turning of the volume adjusting member also controls a coarse volume setting means and a fine volume setting means, the course volume setting means being responsive to a relatively small turning of the volume adjusting member for moving the volume setting member a relatively large axial distance and the fine volume setting means being responsive to a relatively large turning of the volume adjusting member for moving the volume setting member a relatively small axial distance.

Abstract: A pipette includes a housing defining a suction chamber. A piston is configured to move in the suction chamber. A first retainer mechanism includes a first threading configured to limit a motion of the piston in the suction chamber. A second retainer mechanism includes a second threading configured to limit the motion of the piston in the suction chamber, the second threading having a pitch less than a pitch of the first threading.

Abstract: The sampling pipette comprises a body; an arm movable relative to the body parallel to a longitudinal direction of the pipette in order to eject a cone fixed to the body; and a button for controlling movement of the arm. The pipette is arranged in such a manner that the button applies sliding thrust on the arm while the arm is moving relative to the body.

Abstract: A pipette tip and mounting shaft combination in an air displacement pipette, the combination comprising a pipette tip mounting shaft having a radially stepped exterior comprising adjacent substantially cylindrical portions of different diameter and an annular sealing zone including an annular edge seal at an outermost edge of a radially extending shaft transition, a pipette tip including an annular sealing region having an inner sealing surface on a sidewall of the tip which in the sealing region is sufficiently thin as to expand slightly and form an interference fit and air tight seal between the sealing surface and the sealing zone when the sealing zone penetrates the sealing region, and axial penetration limiting means for limiting penetration of the shaft into the tip to limit axial contact between the sealing region and the sealing zone to a narrow annular band comprising the annular edge seal.

Abstract: The sampling pipette includes means for adjusting the volume of liquid to be taken. It includes a locking element that is movable between an inactive position in which it makes the adjustment means unsuitable for performing adjustment and an active position in which it makes the adjustment means suitable for performing adjustment.

Abstract: A multiple pipette (X) comprising a first pipette (1) and a second pipette (2), wherein the first pipette (1) allows a liquid stored in a liquid storing section (17a) to be delivered a plurality of times by a fixed amount each and the second pipette (2) allows a liquid drawn in from outside to be delivered all at a time. The first pipette (1) is designed to deliver a liquid a plurality of times by a fixed amount each, e.g., by utilizing a ratchet mechanism (12d, 13a). The first pipette (1) preferably has a cap (19) removably attached to the front end thereof.

Abstract: A hand-held pipettor comprising a piston received in one end of a cylinder, a pipettor tip removably secured to an opposite end of said cylinder, means for reciprocating said piston through a selected stroke to aspirate fluid into and to expel the thus aspirated fluid from said pipettor tip, mutually spaced stop members operatively associated with said manually driven means for defining the range of said stroke and motor driven means for varying the spacing between said stop members to thereby vary the volume of fluid being aspirated into and expelled from said pipettor tip.

Abstract: A pipetting device for detachably mountable pipette tips, comprising a moving device, a piston movable by the moving device in a cylinder to displace a column of air, an attachment stem for mounting a pipette tip, with an aperture having a connection to the cylinder at the free end, two stops limiting the movement of the piston during the displacement of the column of air, one of which is dislocatable, a precise adjustment device for dislocating the dislocatable stop in parallel with the piston for a precise adjustment of the piston stroke, a coupling device which puts the precise adjustment device into function, when coupled, and puts it out of function, when uncoupled, a rough adjustment device for dislocating the dislocatable stop when the precise adjustment device is uncoupled, for a rough adjustment of the piston stroke, and a measuring and indicating device coupled to the dislocatable stop for measuring the position set for the dislocatable stop and indicating the proportioning volume that matches the p