Abstract: A pipette tip for and method of automatically maintaining pipette tip depth in a fluid during a fluid transfer operation is disclosed. The pipette tip includes, for example, two electrodes that run substantially the full length of the pipette tip for measuring the resistance therebetween when submerged in a conductive fluid. A method is provided of automatically maintaining the depth of the pipette tip in a liquid throughout a pipetting operation, as the liquid surface rises or falls in its container, without any prior knowledge of the container geometry.

Abstract: A dispensing tip holder is used when a dispensing tip is attached to a tip of a pipette, and includes a peripheral wall having a shape surrounding an outer peripheral surface of the dispensing tip, and an insertion portion having an insertion opening into which the dispensing tip is to be inserted. The peripheral wall has a first end into which the dispensing tip is to be inserted, and has a second end provided at a position opposite to the first end. The insertion portion is formed in the peripheral wall such that an outer peripheral surface of the dispensing tip abuts against an edge of the insertion opening, and is formed in the peripheral wall such that a tip of the dispensing tip does not project from the second end of the peripheral wall, when the dispensing tip is inserted into the insertion opening from the first end.

Abstract: Multivolume liquid pipettes with nested plunger and vacuum chamber configurations and methods of using such pipettes are disclosed herein. These pipettes typically include a body and a fluid displacement assembly with a small plunger element slideably received within a larger plunger element, each movable within a vacuum chamber for the precise and accurate control of the displacement of fluid, such as air. In turn, this allows for a single device to aspirate and dispense a broad range of liquids in a dynamic, accurate, and precise manner. In addition, the devices disclosed herein may also include a multi-tiered spring-loaded ejection mechanism to allow the user to use and eject pipette tips of different sizes.

Abstract: A pipette comprises a pipette housing comprising an upper end and a lower end, a nipple configured to contact and retain a pipette tip, a drive apparatus configured to aspirate a liquid specimen into the pipette tip and expel the liquid specimen from the pipette tip, and an ejection apparatus. The ejection apparatus comprises a curved support rotatably mounted within the pipette housing, an ejection rod, a first sensing element positioned on the ejection rod and configured to be guided on a first curve on a perimeter of the curved support, and an operating element coupled to the curved support and configured to rotate relative to the pipette housing. The ejection apparatus is configured to rotate the curved support out of a start position by rotating the operating element. The first curve displaces the first sensing element downward a the ejection rod moves the pipette tip off of the nipple.

Abstract: A pipette device is provided and prevents the corrosion of main metal parts without causing a significant rise in costs. A pipette device includes a piston portion that is movable in order to suck a liquid and an air hole for discharging an air generated from the liquid sucked by the piston portion to an outside. The air is discharged from the air hole in response to movement of the piston portion.

Abstract: A metering head for a metering machine having a carrier having parallel attachments for picking up pipette tips, wherein each attachment has: a tube having a supporting protrusion at the bottom end, at least one sleeve which surrounds the tube and can be axially shifted on the tube, and at least one elastomer O-ring which surrounds the tube, a pressure plate above the sleeves having a plurality of first holes through which the tubes extend, wherein the pressure plate can be shifted along the tubes from a release position into a clamping position where the sleeves are pressed, at the bottom ends, against the adjacent O-rings, and the O-rings are expanded to clamp pipette tips; and a first shifting apparatus connected to the pressure plate moving the pressure plate between the release position and clamping position.

Abstract: Systems and methods that enable automated processing of specimens carried on microscope slides are described herein. Aspects of the technology are directed, for example, to automated slide processing apparatuses capable of dispensing liquids onto microscope slides. Additional aspects of the technology are directed to methods of replacing a reagent pipette in automated slide processing apparatuses. The apparatus can include, for example, a reagent pipette assembly including a reagent pipette moveable between at least one loading position for obtaining reagent from a reagent container at a filling station and at least one dispense position. The apparatus can also include a retainer for releasably securing the reagent pipette. In some embodiments, the reagent pipette assembly includes a locking mechanism for transitioning the retainer from an open configuration for receiving a pipette and a closed configuration for securing a pipette, in e.g., an aligned position within the retainer.

Abstract: In order to be able to adapt a manual dosing device (1), in particular a pipette (2), to differently sized hand dimensions, the manual dosing device (1) at whose main body (3) at least one grip (5) or exchangeable grip is releasable, fastenable or fastened is proposed. Adaptation of the manual dosing device (1) to users having different hand sizes can be performed by removing the grip (5) or by changing the grip (5) and replacing the grip (5) with a grip (5) having different dimensions (FIG. 1).

Abstract: In order to improve the ergonomics of a sampling pipette, the invention provides a control member intended to occupy a nominal central position in which a spring brings a locking member into the locking position thereof of the system for adjustment of the volume to be sampled, the member being able to be axially displaced towards each of the two following positions: a low position for ejecting a cone, in which the control member presses on the cone ejector, the movement from the nominal central position to the low position being carried out against the springs; and a high position for unlocking the braking ring, the movement of the control member from the nominal central position to the high position driving a disengagement element to move the locking member against the spring, until release of the braking ring.

Abstract: An aspirator adapter may comprise a cap portion configured to removably mount on a collection container, a pipette interface portion mounted on the cap portion and configured to mount a pipette to the cap portion, and a gun interface portion mounted on the cap portion and configured to interface with a pipette gun. The pipette interface portion may define a pipette interface passage extending through the cap portion and the gun interface portion defining a gun interface passage extending through the cap portion.

Abstract: This invention relates to methods, systems, and computer program products for verifying dispensing of a fluid from a pipette.

Abstract: Systems and methods are described for a non-contact method for positioning a tip of an object. A light beam of known dimensions is projected and a position of the tip of the object relative to the light beam is adjusted. Light scatter indicative of the tip of the object being positioned within the dimensions of the light beam is detected and a position of the tip of the object is determined based at least in part on the known dimensions of the light beam and the detected light scatter.

Abstract: Nanoliter pipette assembly. The assembly includes a housing containing a working fluid in a working fluid chamber therein and includes a moveable piston within the housing, the piston moveable by a linear actuation mechanism for contact with the working fluid. A tip portion is provided that includes a diaphragm deformable to engage an inner portion of the tip. It is preferred that the diaphragm have a projecting three-dimensional structure for direct contact with a liquid.

Abstract: The invention relates to a pipetting device for pipetting at least one fluid laboratory sample into at least one pipetting vessel, said device having a main body extending along an axis direction, at least one connecting section, to which at least one pipetting vessel can be connected by an at least partially axial connecting movement along the positive axis direction, wherein the at least one connecting section is connected to the main body so as to be movable at least in the axis direction, a spring mechanism, by which the at least one connecting section is supported with spring loading on the main body at least in a first operating state of the pipetting device, such that the at least one connecting section, during the connecting movement, can perform a spring-assisted deflection movement along the positive axis direction, wherein an auxiliary mechanism is provided on the pipetting device and is designed to act on the deflection movement of the at least one connecting section in at least a second operating

Abstract: A pipette tip having the shape of an elongate small tube with a lower opening at the lower end for the passage of liquid, and an upper opening at the upper end, wherein a seat area exists on the inner circumference contiguous to the upper opening, which serves for plugging it onto a standardized conical attachment piece of a pipetting device, wherein the seat area has a retaining area with axially extending ribs projecting radially towards the inside, and below the retaining area a sealing area and is configured such that when the pipette tip is plugged onto the attachment piece with its seat area by a plugging force which ensures retaining and sealing of the pipette tip on the attachment piece, the ribs are partly plastically deformed, and elastic deformation occurs in the seat area outside of the ribs.

Abstract: There is provided a bellows type dispensing tip, a bellows type dispensing apparatus, and a method of bellows type dispensing processing that performs highly precise dispensing processing despite having a simple structure. The apparatus comprises; two or more bellows type dispensing tips having; an accommodating section that is capable of accommodating a liquid or gas in the interior thereof surrounded by a wall face, and that has a deformable deforming wall face in a portion of the wall face, and an opening section communicated with the accommodating section, through which the liquid to be suctioned/discharged can flow in and flow out due to expansion and contraction of the interior caused by deformation of the deforming wall face; and a dispensing head that supports one or two or more of the bellows type dispensing tips, and that performs suction/discharge of the liquid into or from the bellows type dispensing tip, by deforming the deforming wall face of the bellows type dispensing tip.

Abstract: Disclosed here are pipette tips useful for acquiring or dispelling liquids, and include one or more design that may increase fluid delivery precision and/or accuracy, and may reduce certain repetitive motions.

Abstract: A pipette with a displacement unit, a drive unit, means for the detachable connection that detachably connects together the upper housing part and the lower housing part, an ejection device, an end stop, a decoupling device and coupled to the drive device, a lower stop body that upon decoupling of the drive element from the drive device by the decoupling device strikes the actuating end of the ejection extension in order, with further shifting of the actuating element in the actuating direction, to shift downward the ejection extension and the ejection slide.

Abstract: Automated apparatus and methods for dispensing fluids into microplates utilizing microwell covers, the covers comprising open portions to allow a pipette access to one or more wells and impermeable portions which prevent the fluids from getting into wells shielded by the impermeable portion. The open portions and impermeable portions are preferably arranged and sized to align with alternating rows of wells in a particular microplate. Preferred covers are movably positioned on the microplate. Automated dispensing apparatus for use with microplates and microwell covers comprises a programmable controller, and suitable interfaces which allow the apparatus to be programmed, and which control a dispensing head such that pipettes are moved in the desired manner in order to take advantage of the protective features of the microwell covers. The apparatus also preferably comprises at least one transfer mechanism for moving a cover relative to a microplate at a dispensing station.

Abstract: The nozzle (3) is in its lower part formed respectively for receiving a pipette exchangeable tip (19) and is in its upper part releasably connected with the holder (2). In the holder (2) a pressure sleeve (6) is placed as being slidably borne in the holder (2). The pressure sleeve (6) is via a pressure sub-assembly seated in the holder (2) pressed to the sealing means placed between the pressure sleeve (6) and the nozzle (3). The plunger (1) is slidably borne in the pressure sleeve (6) and in the pressure sub-assembly. Due to this, leakproofness of the plunger (1) in the nozzle (3), which is indispensable for a correct and reliable pipette operation, is provided in PIPETTING, ADJUSTMENT or CALIBRATION MODES of the pipette. Simultaneously, in MAINTENANCE MODE of the pipette the sealing means automatically slide out from an abutting surface (2c) of the holder (2).

Abstract: Syringe mounting apparatus includes a body (25,300), and a coupling mechanism (20) on the body having a housing (22) to receive a barrel of a syringe component and means (28) to detachably engage the barrel and thereby interchangeably retain the syringe component. A plunger connector (60) is positioned with respect to the housing for operably coupling a plunger driver to a plunger element in the barrel of a syringe component when it is interchangeably retained by the coupling mechanism. The plunger connector includes means (74) for detachably engaging the plunger element in a manner allowing the plunger driver to effect reciprocatory movement of the plunger element longitudinally of the barrel for drawing fluid into or expelling fluid from the syringe component. Also disclosed are a syringe system, a disposable syringe component, and a syringe component with engagement features.

Abstract: In the case of a tool (140) for handling a sample, which comprises a fastening device (141) for detachably fastening the tool to a tool holder of a sample handling apparatus, and comprises a sample manipulation device, for example realized as a syringe (150), fastened to the fastening device (141), this tool comprises a holding device, for example in the form of a needle guide (160), which, on the one hand, is fastened to the fastening device (141) so as to be movable in a coupling direction (165) and, on the other hand, can be coupled to and decoupled from the tool holder in the coupling direction (165).

Abstract: A high-speed automatic dispensing apparatus capable of preparing samples under different conditions, minimizing waste liquid materials, and realizing high productivity. A dispensing station is also provided. The high-speed automatic dispensing apparatus with a replaceable dispensing head comprises a dispensing head including a plurality of pipettes, a pipette head to which one end of a plunger extending to pass through each pipette is fixed, and a head body part abutting against the pipette head and allowing the pipettes to pass therethrough, a pipette head moving mechanism vertically moving the pipette head, and a drive mechanism horizontally and vertically moving the dispensing head. The dispensing station includes the high-speed automatic dispensing apparatus.

Abstract: A handheld pipetting apparatus for metering liquids, with a handleable pipette housing, at least one accommodation for a fastening portion of a syringe cylinder of a syringe, at least one plunger accommodation in an accommodation body for a plunger fastening portion of a syringe plunger of the syringe, syringe and plunger gripping levers for detachably holding the fastening portion in the accommodation and the plunger fastening portion in the plunger accommodation, at least one displacement device with a displacement chamber and a shiftable chamber wall limiting the same, for displacing a fluid; at least one seat for detachably holding a pipette point, a channel, connecting a hole in the seat with a displacement chamber, and at least one drive device, which is connected to couplable with the accommodation body the and/or the chamber wall, for shifting the accommodation body with respect to the accommodation, the and/or the chamber wall with respect to the displacement chamber.

Abstract: A device, system, and method for passively sealing a vessel containing a fluid and for sampling the fluid without carry-over or cross-contamination between the fluid sampling device, the sealing septum, and the vessel contents. The device includes an actuated septum having a plurality of septum fingers, to passively seal the vessel, and an actuation device, to open the passive seal without carry-over or cross-contamination. Each of the plurality of septum fingers includes a corresponding rib portion. The actuation device can be an actuation ring having an annulus. The plurality of septum fingers and corresponding rib portions are disposed internal or substantially internal to the vessel, while the actuation device is disposed external to the vessel.

Abstract: Highly efficient and rapid filtration-based concentration devices, systems and methods are disclosed with sample fluidic lines and a filter packaged in a disposable tip which concentrate biological particles that are suspended in liquid from a dilute feed suspension. A sample concentrate or retentate suspension is retained while eliminating the separated fluid in a separate flow stream. The concentrate is then dispensed from the disposable tip in a set volume of elution fluid. Suspended biological particles include such materials as proteins/toxins, viruses, DNA, and/or bacteria in the size range of approximately 0.001 micron to 20 microns diameter. Concentration of these particles is advantageous for detection of target particles in a dilute suspension, because concentrating them into a small volume makes them easier to detect. All conduits by which the disposable tip attaches to the instrument are combined into a single connection point on the upper end of the tip.

Abstract: A sealing pipette tip includes features to seal the tip directly against the piston in an air displacement pipette, avoiding the need for a piston seal within the pipette. This configuration reduces potential points of failure, allows the pipette-tip interface to be optimized, and improves liquid handling characteristics of the pipette.

Abstract: A pipette with a displacement unit, a drive unit, means for the detachable connection that detachably connects together the upper housing part and the lower housing part, an ejection device, an end stop, a decoupling device and coupled to the drive device, a lower stop body that upon decoupling of the drive element from the drive device by the decoupling device strikes the actuating end of the ejection extension in order, with further shifting of the actuating element in the actuating direction, to shift downward the ejection extension and the ejection slide.

Abstract: A magnetic coupling system may be used in a fluid displacement apparatus to magnetically couple a drive shaft to a piston. The magnetic coupling system may include first and second magnetic couplers at the ends of the drive shaft and piston, respectively. The first magnetic coupler and second magnetic coupler may be configured to exert an attractive force. A bearing between the magnetic couplers reduces friction and side loading.

Abstract: The invention relates to a sealing assembly for a metering device, in particular a multi-channel metering device. The sealing assembly serves to seal pipette tips with respect to the metering device. A multi-channel metering device comprises a multiplicity of openings arranged in one plane. A sealing plate with holes in the grid of the openings abuts this plane. Each pipette tip is provided with an annular collar which has an abutting face and is pressed against the sealing plate by force closure so as to enclose one hole.

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 transfer device (10) which comprises an outer housing (24), an inner body (26) formed within the housing (24), the inner body (26) having a conduit (66) extending therethrough to provide fluid communication between upper and lower chambers, the conduit (66) having a piercing tip (68) at a lower end, a cap (54)having a top wall and a downwardly extending wall (58), the cap being retained in position such that access cannot be had to the inner body (26), and a pushing member (44) which has at least one leg (48) extending upwardly, the pushing member having an activated position where the leg (48) will extend upwardly to the upper chamber and move the cap (54) such that access may be had to the inner body (26).

Abstract: An air displacement pipette has a tubular pipette tip with an upper section surrounding a locking chamber, and a body section leading from the upper section and tapering downwardly to a reduced diameter end. A tubular mounting shaft on the pipette has a distal end configured and dimensioned for axial insertion into the locking chamber of the pipette tip. Coacting surfaces on the distal end of the mounting shaft and the upper section of the pipette tip establish an axially interengaged relationship between the pipette tip and the mounting shaft in response to insertion of the distal end of the mounting shaft into the locking chamber. A sleeve is axially shiftable on the mounting shaft between a retracted position accommodating the establishment of the axially interengaged relationship, and an advanced position disrupting the axially interengaged relationship to thereby accommodate axial ejection of the pipette tip from the mounting shaft.

Abstract: A self-contained sampling probe characterized by a drive module and a syringe module removably coupled coaxially to the drive module to allow for different syringe modules to be interchangeably coupled to the drive module. The coupling is effected by quick connect and disconnect devices, and the syringe module may carry an identifier. The probe is engageable by a gripper or insertable in an interface device, both of which provide for communication of the probe with other system components.

Abstract: A metering device for utilization with a syringe, which features on a syringe cylinder a fastening portion with at least one axially directed sensing surface projecting from the upside, and at least one alignment nose projecting from the outer perimeter of the fastening portion, and a plunger with a plunger rod, the metering device having an accommodation for the fastening portion of the syringe cylinder, the accommodation having an axial opening for axially inserting the fastening portion into a fastening position, a sensing device disposed in the accommodation with at least one sensing means projecting from a basis surface of the sensing device facing the axial opening, for sensing the at least one sensing surface of a fastening portion inserted in a fastening position.

Abstract: An electronic metering apparatus for metering liquids, with a longitudinal, handleable housing, a drive, arranged in the housing, with an electric motor, at least one displacer device, arranged in the housing or being capable to be arranged on the same, with a displacer element, which is connected to the drive and/or connectable to the same, at least one holding device on the bottom end of the housing for holding a pipette point or a syringe, at least one electric operational control in or on the housing, at least one electric information device in or on the housing, an electric control unit arranged in the housing, which is connected to the electric motor, the electric operational control and the electric information device, and which controls the information device depending on the position and/or previous changes of the position of the displacer element, in order to put out an information concerning the next reasonable dislocation of the displacer element, and an electric power supply.

Abstract: This invention relates to plunger operated liquid dispensers, such as hand held pipettors, which are used to portion liquids. Specifically the invention relates to a reliable removal of a liquid from the liquid dispenser. According to the invention the plunger of the liquid dispenser is arranged into a speeded up movement while removing the liquid. This change in speed is preferably sudden.

Abstract: The invention relates to a dispensing cylinder, a large capacity dispensing device, and a method of using a large capacity dispensing device, and aims at providing a dispensing cylinder, a large capacity dispensing device, and a method of using a large capacity dispensing device, with high quantitativity and capable of suppressing the scale of the device and efficiently utilizing working space, despite the relatively large volumes of fluid handled. The construction comprises: a small diameter section, a large diameter section which communicates with the small diameter section and is capable of holding fluids, a sliding section provided in a slidable manner within the large diameter section which enables fluid to be sucked and discharged to and from the large diameter section through the small diameter section, and a connection section which connects the sliding section in a detachable manner to a suction and discharge mechanism which drives the sliding section.

Abstract: A liquid aspirating and dispensing apparatus and method of using the apparatus. Among other elements, the apparatus includes a liquid handling device having one or more channel members, each of which has a removable liquid holding tip attached, and a signal transmitting device. A signal transmitted from the signal transmitting device may be used in a variety of ways to yield information regarding the performance of the apparatus. This information may be provided via direct detection of the signal by an operator of the apparatus. Alternatively, the signal may be detected by a programmable signal detecting device, interpreted by the apparatus, and then displayed in a form that is understandable to the operator. Furthermore, the liquid holding tip may be modified to enable different forms of signal transmission.

Abstract: A sample dispensing apparatus dispenses a sample from a container accommodating a sample such as blood or urea sampled for checking. This sample dispensing apparatus can prevent internal contamination of the apparatus due to dripping of the sample and abnormal sucking operations caused by drainage, condensation and fixing of the sample. The sample dispensing apparatus according to the present invention comprises a dispensing device for dispensing a sucked sample, a dispensing head provided in the dispensing device, and a disposable nozzle chip dismountably set on the dispensing head. In this apparatus, dispensing of a sample to child sample containers is performed exchanging the child sample containers with new ones. When the state, in which dispensing to the child container cannot be carried out, is continued for a prespecified period of time, the nozzle chip is automatically released from the dispensing head.

Abstract: A pipette nozzle is provided for use on a movable arm on an automated pipette machine. The pipette nozzle includes a body defining a passage therethrough and having at least two seating surfaces provided on the body. The first seating surface is configured to receive and sealingly mate with a first size of pipette tip in a manner such that the first end of the passage is in fluid communication with the first size of pipette tip. The second seating surface is configured to correspondingly receive, sealingly mate and provide passage first end fluid communication with a second size of pipette tip.

Abstract: A sample processing/injection device for liquid chromatography comprises a septum at one end of the device, a processing chamber and injection needle disposed on a second end of the device. A fluid sample is transferred into the device by a transfer needle penetrating the septum of the device. The sample device may be positioned to a receiving component such as an injection valve of an instrument by movement of the transfer needle. The sample is injected into the receiving component through the injection needle of the sample processing/injection device through motive pressure supplied by the transfer needle. The sample processing/injection device reduces sampling steps and improves automation by performing sample processing and injection with a single device.

Abstract: Disclosed is a small volume, liquid dispenser having particular application in the analytical fields. The liquid dispensers can be quickly and reliably filled to a predetermined volume without monitoring liquid flows or volumes or filling times. Various versions of the dispenser and systems utilizing one or more of the dispensers are disclosed.

Abstract: Disclosed is a small volume, liquid dispenser having particular application in the analytical fields. The liquid dispensers can be quickly and reliably filled to a predetermined volume without monitoring liquid flows or volumes or filling times. Various versions of the dispenser and systems utilizing one or more of the dispensers are disclosed.

Abstract: A pipette, comprising a pipette casing which has disposed therein a seat, a piston seat in an accommodating body, mounting devices for reversibly fixing the mounting portion and syringe piston of a syringe within the seats and piston adjusting devices for displacing the accommodating body, wherein the mounting portion and syringe piston are adapted to be slid to their mounting positions through axial apertures, the mounting devices have radially advanceable gripping devices, the gripping devices have syringe gripping levers pivotally supported within the pipette casing and piston gripping levers pivotally supported within the accommodating body, the syringe gripping levers and piston gripping levers have two arms, the syringe gripping levers, at the insides of their actuator arms, having contact points which when their actuator arms are actuated are adapted to be externally pivoted against the actuator arms of the piston gripping levers, the syringe gripping levers have inwardly projecting release levers on t

Abstract: A pipetting device having a modular pipetting unit including a pipetting tip for pipetting of fluid samples and a pump conduit for transferring a negative or positive pressure to the pipetting tip is disclosed. The pipetting tip and a portion of the pump conduit adjoining the pipetting tip mutually define a fluid sample conduit for receiving the fluid samples. The modular pipetting unit is detachably attached to an automated positioning device for positioning the modular pipetting unit. A system and method for pipetting of fluid samples using such a pipetting device are also disclosed wherein pipetting of the fluid samples is performed in such a manner that each pipetted fluid sample volume is smaller than a volume of the fluid sample conduit.

Abstract: Pipetting device with an upper part of the casing, a driving element, arranged in the upper part of the casing, with a movable drive element, a spigot receiver, arranged in the upper part of the casing, at least one claw receiver inside the spigot receiver, a lower part of the casing, at least one displacement equipment, arranged in the lower part of the casing, with a displacement chamber, at least one seat for detachably holding a pipette point, arranged on the lower part of the casing and being connected with the displacement chamber via a channel, a spigot, arranged on the lower part of the casing, to be inserted into the spigot receiver, at least one snap hook, arranged on the spigot, with a claw for engaging into the claw receiver when the spigot is inserted into the spigot receiver, and a springy shaft, which is deflectable transversely to the axis of the spigot in order to lift off the claw out of the claw receiver, a lock release ring, movable on the spigot, a wedge gear on the shaft and the lock rel

Abstract: The invention relates to a pipette tip mounting shaft configuration and a disposable pipette tip having a matching configuration. The mounting shaft includes a locking section located above a lower sealing section. The locking section has outwardly extending locking lobes circumferentially spaced around the mounting shaft and located above a stop member that separates the lower sealing section from the upper locking section. When the mounting shaft is fully inserted into the collar of the mating disposable pipette tip, the tip locks onto the mounting shaft. The bore of the pipette tip includes a circumferential shelf separating its upper collar from the tip sealing area which is located below the circumferential shelf. The locking lobes gently flexes and distorts the pipette tip collar out of round as the mounting shaft is inserted in the pipette tip, rather than stretching the tip collar.

Abstract: The invention relates to a pipette tip mounting shaft configuration and a disposable pipette tip having a matching configuration. The mounting shaft includes a locking section located above a lower sealing section. The locking section has outwardly extending locking lobes circumferentially spaced around the mounting shaft and located above a stop member that separates the lower sealing section from the upper locking section. In certain embodiments, the diameter of the mounting shaft below the stop member is reduced in order to lessen insertion and ejection forces, which is particularly helpful for hand-held multi-channel pipettors. In these embodiments, the lower sealing section contains either a frustoconical sealing section, or an annular groove and a sealing ring, such as a flouroelastomeric O-ring seal.

Abstract: A pipette assembly for automatic pipetting machines including a stepped mandrel and tip for providing a minimum contact seal between the pipette tip and mandrel. The mandrel includes a first cylindrical portion with a first exterior diameter and a second cylindrical portion with a second exterior diameter. Raised bands on the first and second cylindrical portions contact the interior wall of the pipette tip to form seals. Because only a portion of the mandrel, specifically the seal portions, contacts the pipette tip, lower forces are required to insert the tip onto the mandrel.