Methods of processing a sample

Abstract

A method of processing an isolated zone of a sample using a liquid. The method comprises the steps of: - generating an isolated zone of a sample by means of a first fluid reservoir, said first fluid reservoir enclosing a distal end of a second fluid reservoir, and the isolated zone of the sample being sealed against the rest of the sample, - fluidly connecting the isolated zone of the sample with the second fluid reservoir, - dispensing fluid from the second fluid reservoir into the first fluid reservoir, thereby generating a fluid flow on the sample in a first direction in the isolated zone, and - sucking fluid from the first fluid reservoir into the second fluid reservoir, thereby generating a fluid flow on the sample in a second direction in the isolated zone.

Description

[0001] This application is a divisional application of the patent application filed on December 20, 2018, with application number 201880100417.1 (international application number PCT / US2018 / 066850) and entitled "Method for Processing Samples". Technical Field

[0002] This invention relates to a method for treating the isolation zone of a sample using a liquid. Background Technology

[0003] To provide histopathological diagnosis, ex vivo tissue is observed under a microscope. With the advent of personalized medicine and the development of molecular technologies, these tissue sections can be further studied to facilitate treatment decisions, and in some cases, specific regions of the tissue (so-called AOI—region of interest) can be delineated for analysis. For example, in the analysis of tumor samples aimed at determining which drug or drug combination is most suitable for cancer treatment, it may be necessary to isolate tumor cells and normal cells from a mixture of tumors, and subsequently extract and purify nucleic acids, proteins, or other subcellular elements and molecules from sections of frozen and formalin-fixed paraffin-embedded (FFPE) tumor tissue. Currently, tissue sections are collected by mechanically scraping the region of interest from the surface of a tissue slide or tissue block, or alternatively by isolating the tissue section using laser capture microdissection (LCM) and related techniques. The tissue section is then subjected to additional steps using chemical and biochemical methods—such as deparaffinization, cell lysis, and purification. For smaller AOIs, mechanical scraping using, for example, a sharp knife often has low spatial accuracy and is also susceptible to contamination by cells or molecules from the surrounding area. LCM is useful for smaller areas, but it is expensive and does not benefit clinical workflow. Summary of the Invention

[0004] One object of the present invention is to provide alternative devices and methods that are specifically targeted and processed in an automated manner for localized restricted areas of interest of a sample provided on a surface, particularly a biological sample, such as a tissue section on a microscope slide, or a locally restricted area of ​​interest of a prepared sample, such as a tissue section embedded in paraffin, as preparation for one or more subsequent analytical steps.

[0005] This objective is achieved by a pipette tip extension that can be attached to a pipette tip. The pipette tip extension includes a proximal end, a distal end, and an outer wall extending between the proximal and distal ends. The outer wall has an outer side and an inner side and encloses an inner cavity defined by the inner side of the outer wall. A receiving aperture for insertion of a pipette tip is formed at the proximal end of the outer wall. A dispensing aperture is also formed at the distal end of the outer wall. The pipette tip extension also includes one or more spacer elements disposed on the inner side of the outer wall and extending into the inner cavity. The one or more spacer elements are sized to establish a fluid aspiration zone adjacent to the inner side of the outer wall. The fluid aspiration zone extends from the dispensing aperture to the receiving aperture. The fluid aspiration zone is fluidly connected to the surrounding atmosphere at the receiving aperture.

[0006] One or more spacers are configured to allow the formation of at least one internal channel or fluid aspiration zone when a pipette tip extension is attached to a pipette tip. Each spacer ensures that the pipette tip inserted into the pipette tip extension is positioned at a defined distance from the inner wall of the pipette tip extension, thereby allowing the formation of a fluid aspiration zone between the inserted pipette tip and the inner side of the pipette tip extension, and preventing the inserted pipette tip from completely abutting against the inner side of the outer wall of the pipette tip extension. Thus, the spacers(one or more) act as partitions that subdivide the interior of the pipette tip extension into a fluid aspiration zone located between the spacer and the inner wall of the pipette tip extension.

[0007] A spacer element is sufficient to separate the inserted pipette tip from the inner side of the outer wall, forming a channel between the outer side of the inserted pipette tip and the inner side of the pipette tip extension. This channel receives fluid that will move between the pipette tip and the pipette tip extension. The use of two or more spacers may be preferred when it is desired to enclose the channel or fluid aspiration area of ​​the inserted pipette tip. Whether using one or multiple spacers, the spacers do not extend circumferentially so that the pipette tip extension never closes to the receiving orifice. The spacers are described below by using the plural and singular interchangeably.

[0008] The spacers subdivide the cavity into a pipette tip receiving area, which is positioned adjacent to the fluid aspiration area and along the central axis of the pipette tip extension, adjacent to the stop surface of the spacers, and corresponding to the later position of the inserted pipette tip. The depth of each spacer, corresponding to its length, specifically defines the volume of liquid that can be received in the fluid aspiration area, by which the corresponding spacer protrudes from the inner wall of the pipette tip extension toward the central axis. Furthermore, the fluid aspiration area is restricted by the outer wall of the inserted pipette tip and the inner wall of the pipette tip extension.

[0009] In exemplary embodiments, the pipette tip extension may be made of a chemically inert material, such as a plastic polymer, like polypropylene, polyethylene, or a fluoropolymer; or of glass or metal, such as aluminum or steel. Plastics offer advantages such as chemical inertness, relatively low production costs, and slight deformability. This allows the pipette tip extension to be attached to the pipette tip via a friction fit, and also allows for a sealing connection, for example, with a surface when the pipette tip extension is placed on such a surface, such as a microscope slide. It is also a preferred material for disposability. However, the pipette tip extension can also be attached by means of a form fit, such as a tongue and groove joint, and / or by equipping the distal end of the pipette tip extension with a sealing element to achieve a sealing connection with a surface, such as a microscope slide. Another suitable chemically inert material is polytetrafluoroethylene (PTFE).

[0010] In another exemplary embodiment, viewed orthogonally to the central axis of the pipette tip extension, the receiving hole may have a circular cross-section or an off-center cross-section. The receiving hole is adapted to allow insertion of a pipette tip (e.g., a disposable pipette tip made of plastic or a so-called fixed pipette tip made of metal).

[0011] In another exemplary embodiment, the inner diameter of the receiving hole of the pipette tip extension may be 6 mm, and the outer diameter of the pipette tip into which it should enter the receiving hole may be approximately 1 mm. This extension is suitable, for example, when using a disposable pipette tip with an outer diameter of approximately 5 mm that should rest within the receiving hole of the pipette tip extension, or when using a fixed pipette tip with an outer diameter of approximately 4 mm. The space between the inner diameter of the receiving hole and / or the inner side of the outer wall may be controlled by one or more spacer elements.

[0012] In the context of this invention, a disposable pipette tip is a pipette tip that can be automatically received and / or ejected, for example, by a liquid handling device. It is typically made of plastic, and the connection to the liquid handling device can be achieved by slightly deforming the plastic to obtain a frictional fit between the tip and the device.

[0013] In the context of this invention, the fixed pipette tip is mechanically attached to the liquid handling device via a form-fit, for example, by being screwed onto the device. Installation and removal typically require manual interaction. The fixed pipette tip is usually made of metal to ensure a stable shape.

[0014] The receiving port at the proximal end of the suction tip extension is at least partially open during use and is therefore not completely closed, for example, by a cover, seal, the suction tip to which the suction tip extension is attached, or a combination thereof. By maintaining openness to the ambient atmosphere, adequate pressure equalization is ensured as liquid is dispensed from the suction tip into the fluid aspiration zone of the attached suction tip extension.

[0015] In a further exemplary embodiment, viewed orthogonally to the central axis of the pipette tip extension, the dispensing orifice at the distal end of the pipette tip extension may have a circular shape or a circular cross-section. However, the cross-section of the dispensing orifice may deviate from a circular shape, for example, it may be elliptical, triangular, or may have another form, such as a polygonal form. The shape and / or size of the dispensing orifice may be adapted to a specific application or use of the pipette tip extension, such as to a specific area of ​​interest in the tissue section to be targeted. By way of example, a particularly suitable size for a dispensing orifice with a substantially circular shape may be a diameter of 1.65 mm. Suitable diameters may range from 0.2 mm to 7 mm, particularly from 1 to 2 mm.

[0016] In another exemplary embodiment, the spacer element may be, for example, an inner rod, but other types of protrusions, such as nose-shaped protrusions, are also possible on the inner side of the outer wall of the pipette tip extension, as are variations (e.g., straight, serpentine, or wavy rods). Combinations of different types or forms of protrusions are possible. Irregular forms are particularly suitable for providing additional mixing effects on the liquid introduced into the pipette tip extension. It may be possible to provide only one inner spacer element on the inner side of the outer wall, provided it is suitable to allow the formation of a fluid aspiration zone within the lumen of the pipette tip extension. With only one spacer element, the pipette tip receiving area may be eccentric relative to the central axis of the pipette tip extension. Multiple spacer elements are also possible, which allows for a more precise definition of the positions of the pipette tip receiving area and the fluid aspiration zone within the lumen of the pipette tip extension. However, the use of multiple spacer elements also allows for eccentric positioning of the pipette tip within the lumen of the pipette tip extension. In particular, by coordinating the depth of each spacer element according to the internal form of the pipette tip extension, it is possible to define whether the pipette tip will be positioned in a centered or eccentric manner within the pipette tip extension.

[0017] In embodiments of the invention (which may be combined with any other embodiments mentioned herein, unless conflicting), at least one or more spacer elements provide a stop surface oriented about the central axis of the suction tip extension. In the context of the invention, the stop surface of the spacer element is a contact point or contact surface that is abutted by the suction tip when the suction tip extension is attached to the suction tip. Therefore, the stop surface marks a boundary at that specific location between the fluid aspiration area and the suction tip receiving area.

[0018] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless conflicting), one or more spacer elements on the inner side of the outer wall extend in a direction from the proximal region of the suction tip extension to the distal region of the suction tip extension. The spacer elements are, for example, constructed as inner rods of equal or varying widths, and / or the spacer elements are further extended in the direction from the proximal end to the distal end compared to their wider portion, where the width is a transverse dimension. The use of at least two or more extended spacer elements is particularly suitable for the accurate positioning of the suction tip within the suction tip extension. For example, it is possible to have a large number of shorter spacer elements positioned in an alternating manner, such as in an irregular matrix and / or in a direction from the proximal end to the distal end, or a smaller number of spacer elements, longer and arranged in a regular matrix on the inner side of the outer wall, or a mixture thereof. As a supplement or alternative provision, it is foreseeable that, for example, an elastic plastic material may be provided to the spacer elements, which can be applied by a two-component injection molding step, to enhance the holding force of the suction tip extension on the suction tip.

[0019] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the spacer element extends substantially continuously from the proximal region of the suction tip extension to the distal region of the suction tip extension. This arrangement is particularly suitable for the spacer element (which is configured, for example, as an inner rod) and, for example, allows for simplification of the manufacturing process in injection molding.

[0020] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), the spacer element is arranged flush with the proximal end of the pipette tip extension, for example from the top to the bottom of the pipette tip extension; or offset relative to the proximal end of the pipette tip extension.

[0021] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the stop surfaces of the spacer elements collectively form a common stop surface in the lumen, which can be abutted against by the inserted pipette tip, i.e., can begin to align with the inserted pipette tip. The spacer elements are specifically sized such that the common stop surface is closer to the central axis toward the distal end of the pipette tip extension. The common stop surface respectively contributes to the definition of the boundaries of the pipette tip receiving area and the fluid aspiration area.

[0022] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the outer wall of the pipette tip extension is a circumferential wall that tapers gradually toward the lower end of the pipette tip extension. The outer wall may define the form and dimensions of the pipette tip extension, which may be, for example, a rectangular hollow body, tapering at least partially or completely in a conical shape in a distal region. The pipette tip extension may also have an axially symmetrical form, but an axially asymmetrical form is also possible. For example, a 30 mm long pipette tip extension is suitable when a 60 mm long, 200 μl volume pipette tip should be used and 100 μl of liquid should be dispensed and / or aspirated. The outer wall may taper gradually with respect to its total length, or may also include, for example, a cylindrical segment, preferably located at the proximal end of the pipette tip extension.

[0023] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), the stop surface of each spacer element is substantially parallel to the inner side of the outer wall. This is particularly advantageous when the outer wall of the pipette tip extension is shaped to fit the outer wall of the pipette tip to be inserted, that is, when the two walls, namely the outer wall of the pipette tip extension and the outer wall of the pipette tip, are arranged parallel to each other when assembled.

[0024] For example, it is particularly useful to adapt the number of spacers and / or the depth of each spacer to the external dimensions of the pipette tip to which the pipette tip extension should be attached. This adaptation may, for example, take into account the external dimensions of the pipette tip and / or the expected friction between the inserted pipette tip and the pipette tip extension, depending on whether a tight frictional fit or only a loose insertion is expected. It may also be useful to adapt these parameters to the volume of liquid that should be received in the fluid aspiration zone of the pipette tip extension. For example, the aspiration volume of the pipette tip extension may correspond to the nominal volume of the pipette tip to which the pipette tip extension should be attached.

[0025] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), the outer wall, and particularly the inner side of the outer wall of the pipette tip extension, has a shape (i.e., the shape of the outer wall) suitable for a pipette tip to be inserted into the pipette tip extension. Suitable also means, in particular, that at least a portion of the outer wall of the pipette tip extension has a shape similar to that of the pipette tip, but at a different size, preferably a larger size.

[0026] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless conflicting), the pipette tip extension includes a constriction element for controlling the insertion depth of the pipette tip within the pipette tip extension. The constriction element defines a gap having a clearance height between the distal end of the inserted pipette tip and the distal end of the pipette tip extension. The pipette tip extension is attached to the pipette tip in such a way that the distal ends of both the pipette tip extension and the pipette tip point in substantially the same direction. The same applies to the proximal ends of both the pipette tip extension and the pipette tip.

[0027] The constriction element serves as a stop element, limiting the insertion depth of the pipette tip when the pipette tip extension is attached to the pipette tip. The constriction element should specifically prevent the distal end of the inserted pipette tip from being positioned flush with the distal end of the pipette tip extension or even protruding from the dispensing orifice of the pipette tip extension. By limiting the insertion of the pipette tip to a defined depth within the lumen of the pipette tip extension according to the invention, a gap or corresponding gap height is defined, which is generated when the pipette tip is inserted until insertion stops at the constriction element.

[0028] The gap height (which is generated when the suction tube tip is inserted in a controlled manner by means of a constriction element) can be, for example, 0.1 mm to 1 mm.

[0029] In the context of this invention, the gap describes the space between the distal end of the pipette tip extension and the distal end of the pipette tip, which is created when the pipette tip extension and the pipette tip are assembled. The gap serves as a fluid connection between the lumen of the pipette tip and the fluid aspiration area of ​​the pipette tip extension, and is also part of the fluid aspiration area. When the distal end of the pipette tip extension is placed on a surface (e.g., the surface of a microscope slide with tissue sections), the gap can be limited relative to the distal end of the pipette tip extension by using said surface to close the distribution orifice of the extension. If the distribution orifice of the pipette tip extension is closed, fluid flow between the lumen of the pipette tip and the pipette tip extension is possible. Depending on the internal geometry at the distal end of the pipette tip, the volume and flow rate of the liquid can be affected. Higher flow rates, in particular, maximize the shear stress of the liquid on the tissue, while the flow must be sufficient to ensure that the liquid can access the entire area of ​​the surface of the targeted tissue covered by the distribution orifice of the pipette tip extension.

[0030] The constriction element may be located within the lumen of the pipette tip extension, or may be positioned in other ways as illustrated herein.

[0031] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the contraction element is formed by at least one of the following: The stop surface or portion thereof of one or more spacer elements, the stop surface being oriented about the central axis of the suction tip extension; and / or One or more spacer elements, each distal end being an additional protrusion of the spacer element toward the central axis of the pipette tip extension, and providing abutment for the distal end of the pipette tip to offsetly position the distal end of the pipette tip toward the distal end of the pipette tip extension, the offset corresponding to the gap height; and / or The inner side of the outer wall, which protrudes toward the central axis of the suction tip extension in the distal region of the suction tip, and provides abutment for the distal end of the suction tip; and / or One or more support rods extend laterally relative to the central axis of the suction tube tip extension.

[0032] The contraction element can also be formed, for example, by other portions of the spacer element.

[0033] When the constriction element is formed by the stop surface or portion thereof of one or more spacers, the dimensions of the spacers are adjusted such that—when the suction tip is inserted into the suction tip extension—the suction tip abuts against the stop surface, and reaches its end position within the lumen before the distal end of the suction tip reaches the distal end of the suction tip extension. In this case, in particular, the depth of the spacer defines the extent to which the spacer extends into the lumen and which depth can be used to define the gap height.

[0034] When the constriction element is formed by the distal ends of one or more spacers (the distal ends of the spacers being the ends pointing substantially in the same direction as the distal ends of the pipette tip extension), the distal ends of the spacers are offset to the distal ends of the pipette tip extension and can limit the lumen to a minimum lateral extension of the lumen. This can be achieved, for example, because the distal ends of the spacers include additional protrusions that extend further into the lumen. This additional protrusion is configured to be abutted by the distal end of the inserted pipette tip and can then hold the pipette tip within a defined insertion depth within the pipette tip extension. In the resulting end position of the inserted pipette tip, its distal end is offset to the distal end of the pipette tip extension. This offset, corresponding to the gap height, allows for fluid connection between the pipette tip and the attached pipette tip extension.

[0035] When the constriction element is formed through the inside of the outer wall (which tapers distally and toward the central axis of the pipette tip extension at least in the distal region), the inside of the outer wall immediately includes a protrusion that allows the distal end of the pipette tip to be placed to a depth.

[0036] When the constriction element is formed by one or more support rods (which extend laterally relative to the central axis of the pipette tip extension), the support rods substantially cover the entire diameter of the inner cavity of the pipette tip extension, for example, in the form of support rings. Such support rods can be arranged in the distal region of the pipette tip extension, or they can be arranged flush with the distal end, thus substantially covering the entire cross-sectional extension of the dispensing orifice. For example, one support rod may be sufficient to position the distal end of the inserted pipette tip at a defined height offset from the dispensing orifice of the pipette tip extension. However, it is also possible to provide two or more support rods arranged intersectingly at the distal end over the entire cross-sectional extension of the pipette tip extension.

[0037] It is also possible to provide several constriction elements with different constructions in a single pipette tip extension to allow the pipette tip extension to be used with different types of pipette tips.

[0038] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the constriction element is formed by a support rod extending laterally relative to the central axis of the suction tube tip extension, the support rod forming a fluid-permeable sieve structure which is joined to the inner side of the outer wall or an extension of the inner rod.

[0039] The advantage of using a constriction element is that the insertion depth of the pipette tip within the pipette tip extension can be controlled by a physical structure, which can be provided within the pipette tip extension, on the pipette tip itself, or as a separate insert. Controlling the insertion depth ensures that a gap is left below the distal end of the pipette tip when it is positioned within the pipette tip extension. This gap allows liquid to be transported through the gap and the sample from the pipette tip to the fluid aspiration area of ​​the pipette tip extension, for example, when the dispensing orifice of the pipette tip extension is closed, for example, by the prepared sample itself or by a portion of the sample's surface. The gap serves as a fluid connection between the inner cavity of the pipette tip and the fluid aspiration area of ​​the pipette tip extension. In an advantageous embodiment, one or more spacer elements are arranged such that a continuous fluid aspiration area is created along the inner side of the pipette tip extension, meaning that, preferably, no isolating channels are created, but rather each created fluid aspiration area is fluidly connected to the other fluid aspiration areas. This ensures that the homogeneity of the liquid moving through the sample is maintained between the pipette tip and the pipette tip extension.

[0040] While the constriction element is not mandatory for controlled insertion of the pipette tip into the pipette tip extension, it serves as an additional protection to ensure a repeatable flow field (i.e., repeatable gap height) above the sample, because the insertion depth can be individually controlled by the force applied during insertion. This is to prevent variations in gap height caused, for example, by geometric tolerances in the manufacture of the pipette tip extension or the pipette tip, or by variations in the surface properties of the individual components. As a supplementary or alternative provision, it is foreseeable, for example, that an elastic plastic material may be provided to the constriction element, which can be applied via a two-component injection molding step, to enhance the holding force of the pipette tip extension on the pipette tip.

[0041] In an embodiment of the invention (which may be combined with any other embodiment to be mentioned, unless there is a conflict), the suction tube tip extension includes at least two spacer elements, preferably at least three spacer elements, said spacer elements being configured as extension rods. For example, the spacer elements may be equidistant or asymmetrically spaced.

[0042] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the outer wall includes a seal at the distal end for sealing the dispensing orifice when the pipette tip extension is placed distally on a surface or inserted into a sample. Exemplarily, the distal end of the pipette tip extension may be secondary injection molded, for example, using an elastic material (e.g., elastic plastic).

[0043] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the seal is provided by a separate material at the distal end of the suction tip extension, the seal being provided by secondary injection molding or as an attachable seal.

[0044] In an embodiment of the present invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the pipette tip extension is constructed as a two-part component, wherein the two parts include: - The first upper part provides a receiving hole; and - The second lower section provides a dispensing hole; The first and second parts can be inserted together to form a pipette tip extension; and The second part is made of sealing material.

[0045] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the first portion further includes one or more spacer elements, and the second portion further includes a constriction element for controlling the insertion depth of the suction pipette tip.

[0046] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the pipette tip extension includes two pipette tip receiving areas for receiving two pipette tips. Each pipette tip receiving area is configured to receive one pipette tip. In this configuration, the pipette tip extension is configured for processing a separate area of ​​the sample in each pipette tip receiving area. The pipette tip extension may include two seals, each seal individually surrounding the dispensing orifice of each pipette tip receiving area (i.e., each pipette tip when inserted).

[0047] Another aspect of the invention relates to an assembly comprising a pipette tip extension according to the invention and at least one pipette tip as known in the art.

[0048] Another aspect of the invention relates to an assembly comprising at least one pipette tip extension as described above and a carrier for storing and / or holding one or more pipette tip extensions. The carrier includes one or more receiving portions, wherein each receiving portion is formed for holding and / or storing one pipette tip extension.

[0049] In an embodiment of the assembly (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), at least one receiving portion of the carrier (preferably each receiving portion) includes a stop that can be abutted against by the distal end of the suction tip when the suction tip is inserted into a suction tip extension stored in the receiving portion. The stop functions as a constriction element that extends through a dispensing orifice into the lumen of the suction tip extension when the suction tip extension is stored in the receiving portion, thereby defining the clearance height between the distal end of the inserted suction tip and the distal end of the suction tip extension.

[0050] Therefore, in this embodiment, the constriction element is not located inside the suction tip extension, but rather in the corresponding carrier.

[0051] Another aspect of the invention relates to a suction pipette tip. The suction pipette tip is formed by a circumferential outer wall having an outer side and an inner side, and enclosing an inner cavity defined by the inner side of the outer wall. The circumferential outer wall includes a proximal section for attachment to a suction device, the proximal section including a proximal orifice. The circumferential outer wall further includes a distal section including a distal orifice serving as an inlet and / or outlet for a liquid, and an intermediate section therebetween. The suction pipette tip further includes one or more spacer elements on the outer side of the outer wall, each spacer element being disposed on the intermediate or distal section of the outer wall and projecting away from the outer wall.

[0052] In other words, the pipette tip includes a proximal end, a distal end, and a circumferential outer wall that extends between the proximal and distal ends and tapers towards the distal end. The outer wall, having outer and inner sides, encloses an inner cavity defined by the inner side of the outer wall. The outer wall forms a receiving orifice at the proximal end for attachment to a pipetting device and a dispensing orifice at the distal end for aspiration and dispensing of liquid. The pipette tip further includes one or more spacer elements on the outer side of the outer wall. Each spacer element provides a stop surface facing away from the outer side of the outer wall of the pipette tip. The spacer elements are arranged at a height on the outer wall that ensures that a pipette tip extension attached to the distal end of the pipette tip can abut against one or more spacer elements, which is naturally the distal segment of the pipette tip.

[0053] In exemplary embodiments, pipette tips may be made of chemically inert materials, such as plastic polymers (e.g., polyethylene or polypropylene) or metals (e.g., stainless steel or aluminum). Plastic materials offer advantages such as chemical inertness, relatively low production costs, and slight deformability. Pipettes made of plastic materials are also known as disposable pipette tips (as previously defined) and are typically used for samples with a high risk of contamination. However, pipette tips may also be made of another chemically inert material (e.g., metal). Pipettes made of metal are also known as stationary tips, as previously defined. They are typically multipurpose tips that are cleaned between different applications.

[0054] In an exemplary embodiment, the receiving orifice may have a circular cross-section (viewed orthogonally to the central axis of the suction tip extension). The receiving orifice is configured to fluidly connect the suction tip to a suction device, such as to receive the suction cone of a liquid handling device, or to be inserted into the suction tip. The dispensing orifice may also have a circular shape or a circular cross-section (viewed orthogonally to the central axis of the suction tip). The dispensing orifice is configured to release and receive volumes of fluid.

[0055] In the context of this invention, the fluid can be any type of liquid or gas, such as a liquid sample, reagent, buffer, etc. The fluid can also be a mixture of different liquids (e.g., an emulsion), a mixture of different gases, a mixture of liquid and gas (i.e., an aerosol), or a mixture of liquid and solid particles distributed within said liquid (i.e., a suspension). Solid particles can be, for example, abrasive particles (e.g., sand), or magnetic particles. However, the fluid is preferably a liquid or a gas.

[0056] One or more spacers are configured to allow the formation of an internal channel or fluid aspiration zone between the pipette tip and the pipette tip extension when the pipette tip is inserted into the pipette tip extension. The pipette tip extension includes a proximal end, a distal end, and an outer wall extending between the proximal and distal ends. The outer wall, having outer and inner sides, encloses an inner cavity defined by the inner side of the outer wall. The outer wall forms a receiving aperture at the proximal end for insertion of the pipette tip. The outer wall further forms a dispensing aperture at the distal end. For example, a pipette tip extension may be designed similarly to a pipette tip extension as already described, but without any spacers. Each spacer element ensures that the pipette tip (inserted into the pipette tip extension) is positioned at a defined distance from the inner wall of the pipette tip extension, thereby allowing the formation of a fluid aspiration zone between the inserted pipette tip and the inner side of the pipette tip extension, and preventing the inserted pipette tip from completely abutting against the inner side of the outer wall of the pipette tip extension. Therefore, the spacer element acts as a separator that allows the formation of a fluid aspiration zone within the lumen of the pipette tip extension. This fluid aspiration zone is formed by the spacer elements of the pipette tip, the outer side of the pipette tip, and the inner wall of the pipette tip extension. The depth of each spacer element corresponds to the length by which the corresponding spacer element protrudes from the outer side of the outer wall of the pipette tip, which specifically defines the volume of liquid that can be received in the fluid aspiration zone.

[0057] In exemplary embodiments, the spacer element may be, for example, an outer rod, but other types of protrusions, such as nose-shaped protrusions, are also possible on the outer side of the outer wall of the pipette tip, as well as variations, such as straight, serpentine, or wavy rods. Combinations of different types or forms of protrusions are possible. Irregular forms are particularly suitable for providing an additional mixing effect on liquids introduced into a pipette tip extension to which the pipette tip is attached.

[0058] In exemplary embodiments, it may be possible to attach a single spacer element to a pipette tip, provided it is suitable for allowing the formation of a fluid aspiration zone within the lumen of the pipette tip extension. With only one spacer element, the pipette tip can be positioned off-center relative to the central axis of the attached pipette tip extension. Multiple spacers are also possible, allowing for more precise positioning of the pipette tip within the attached pipette tip extension. The use of multiple spacers also allows for off-center positioning of the pipette tip within the pipette tip extension. Specifically, by coordinating the depth of each spacer element according to the internal shape of the pipette tip extension to be attached, it is possible to define whether the pipette tip will be positioned centrally or off-center within the pipette tip extension.

[0059] In the context of this invention, the stop surface of the spacer element of the suction tube tip is a contact point or contact surface, which is abutted against the inner wall of the suction tube tip extension.

[0060] In embodiments of the invention (which may be combined with any other embodiments mentioned and to be mentioned, unless there is a conflict), the spacer elements on the outer side of the outer wall extend in a direction from the middle section of the pipette tip toward the distal section of the pipette tip. The spacer elements are configured, for example, as outer rods of the same or varying width, and / or as outer rods that are longer than their wider counterparts in a direction from proximal to distal, wherein the width is a transverse dimension. When suitable for separating the pipette tip from the pipette tip extension, the spacer elements may extend further from the proximal region of the pipette tip toward the distal region of the pipette tip. The use of at least two or more extended spacer elements is particularly suitable for the accurate positioning of the pipette tip within the pipette tip extension, similar to the spacer elements discussed previously. For example, it may be possible to have a large number of shorter spacer elements positioned in an alternating manner, for example, in an irregular matrix and / or in a direction from proximal to distal, or a smaller number of spacer elements, longer and arranged in a regular matrix on the inner side of the outer wall, or a mixture thereof.

[0061] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), the spacer element extends substantially continuously to the distal region of the suction nozzle. This arrangement is particularly suitable for the spacer element (which is configured, for example, as an inner rod) and, for example, allows for simplification of the manufacturing process in injection molding. The spacer element may be arranged flush with the proximal end of the suction nozzle (e.g., from the top to the bottom of the suction nozzle) or offset from the proximal end of the suction nozzle.

[0062] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless conflicting), one or more spacer elements provide a stop surface facing away from the outer wall. The stop surfaces of the spacer elements collectively form a common stop surface that can be abutted against by an attached pipette tip extension. The common stop surface abuts against the inner side of the attached pipette tip extension and provides a tight base for the pipette tip within the attached pipette tip extension. The common stop surface respectively defines the boundaries of the pipette tip receiving area and the fluid aspiration area.

[0063] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless conflicting), the outer wall of the pipette tip is a circumferential wall that tapers gradually toward the lower end of the pipette tip. The outer wall may define the general shape and internal dimensions of the pipette tip. For example, the outer wall may give the pipette tip a substantially rectangular hollow body shape, which tapers gradually or completely in a conical shape, for example, in a distal region. The outer wall may taper gradually along its total length in a regular manner or in different steps, or may also include, for example, a cylindrical segment. The pipette tip may also have an axially symmetrical form, but an axially asymmetrical form is also possible. The internal shape or geometry of the pipette tip is particularly suited to the nominal liquid volume and may also be suitable for the different operational requirements of the pipette or aspiration device with which the pipette tip will be used.

[0064] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the stop surface of each spacer element is substantially parallel to the outer side of the outer wall of the suction tube tip.

[0065] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the pipette tip is configured to be used as a disposable pipette tip or as a fixed pipette tip.

[0066] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the pipette tip includes one or more constriction elements configured to limit the insertion depth of the pipette tip within the pipette tip extension.

[0067] Another aspect of the invention relates to an assembly comprising a pipette tip and a pipette tip extension, the pipette tip including at least one spacer element. The pipette tip extension of this assembly includes a proximal end, a distal end, and an outer wall extending between the proximal and distal ends of the pipette tip extension. The outer wall of the pipette tip extension has an outer side and an inner side, and encloses an inner cavity defined by the inner side of the outer wall of the pipette tip extension. Furthermore, the outer wall of the pipette tip extension forms a receiving hole at the proximal end for inserting a pipette tip, and a dispensing hole at the distal end. For example, the pipette tip extension is designed similarly to the pipette tip extension already described, but without any spacer element. The suction tip extension can be attached to the distal end of the suction tube by inserting it through a receiving hole at the proximal end of the suction tip extension, for example until the inner side of the suction tip extension abuts against the spacer element of the suction tube tip.

[0068] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the outer wall of the suction tube tip extension of the assembly has a shape suitable for the suction tube tip to be inserted.

[0069] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the pipette tip and / or pipette tip extension includes a constriction element for controlling the insertion depth of the pipette tip into the pipette tip extension, the constriction element defining a gap having a gap height between the distal end of the inserted pipette tip and the distal end of the pipette tip extension.

[0070] The constriction element serves as a stop element, limiting the insertion depth of the pipette tip when it is inserted into the pipette tip extension. The constriction element should specifically prevent the distal end of the inserted pipette tip from being positioned flush with the distal end of the pipette tip extension or even protruding from the distribution hole of the pipette tip extension. By limiting the insertion of the pipette tip to a defined depth within the lumen of the pipette tip extension according to the invention, a gap or corresponding gap height is defined, which is generated when the pipette tip is inserted until insertion stops at the constriction element. The gap height generated when the pipette tip is inserted in a controlled manner by means of the constriction element can be, for example, from 0.1 mm to 1 mm.

[0071] The gap created when the pipette tip is inserted provides fluid connection between the inner cavity of the pipette tip and the inner cavity of the pipette tip extension. Controlling the gap height by providing one or more constriction elements allows for control of fluid flow between the pipette tip and the attached pipette tip extension. As previously mentioned, another measure for controlling fluid flow is the control of the size of the dispensing orifice. In another embodiment discussed later, the gap is closed by sealing the dispensing orifice at the distal end of the pipette tip extension, since the distal end is placed in a sealing manner onto a surface (e.g., the surface of a microscope slide on which tissue sections are fixed).

[0072] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the contraction element is formed by at least one of the following: The stop surface of the spacer element of the suction pipette tip; The inner side of the outer wall of the suction tip extension, the outer wall protruding toward the central axis of the suction tip extension in the distal region of the suction tip extension, and providing abutment for the distal end of the suction tip; One or more support rods of the suction tube tip extension extend laterally relative to the central axis of the suction tube tip extension.

[0073] When the constriction element is formed by the stop surface of the spacer element, the dimensions of the spacer element are adjusted such that—when the suction tip is inserted into the suction tip extension—the suction tip abuts against the inner wall of the suction tip extension with the stop surface and reaches the end position within the cavity, wherein the distal end of the suction tip has not yet reached the distal end of the suction tip extension. In this case, in particular, the depth of the spacer element defines the extent to which the spacer element extends into the cavity and which depth can be used to define the gap height.

[0074] When the constriction element is formed through the inner side of the outer wall of the suction tip extension (which tapers gradually toward the distal end and toward the central axis of the suction tip extension, at least in the distal region of the suction tip extension), the inner side of the outer wall immediately includes a protrusion that allows the distal end of the suction tip to be placed to a depth.

[0075] When the constriction element is formed by one or more support rods (which extend laterally relative to the central axis of the pipette tip extension), the support rods substantially cover the entire cross-sectional extension of the inner cavity of the pipette tip extension, thereby forming, for example, a support ring. Such support rods can be arranged in the distal region of the pipette tip extension, or can be arranged flush with the distal end, thus substantially covering the entire cross-sectional extension of the dispensing orifice. For example, one support rod may be sufficient to position the distal end of the inserted pipette tip at a defined height offset from the dispensing orifice of the pipette tip extension. However, it is also possible to provide two or more support rods arranged intersectingly over the entire cross-sectional extension of the pipette tip extension at the distal end.

[0076] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the constriction element is formed by a support rod of the suction tube tip extension that extends laterally relative to the central axis of the suction tube tip extension. The support rod forms a fluid-permeable sieve structure that is joined to the inner side of the outer wall or to an extension of the inner rod.

[0077] The advantage of using a constriction element is that the insertion depth of the pipette tip within the pipette tip extension can be controlled by a physical structure, which can be provided within the pipette tip extension, on the pipette tip itself, or as a separate insert. Controlling the insertion depth is important to ensure that a gap is left below the distal end of the pipette tip when it is positioned within the pipette tip extension. This gap allows liquid to be transported through the gap and the sample from the pipette tip to the fluid aspiration area of ​​the pipette tip extension, for example, when the dispensing orifice of the pipette tip extension is closed, for example, by the prepared sample itself or by a portion of the sample's surface. The gap serves as a fluid connection between the inner cavity of the pipette tip and the fluid aspiration area of ​​the pipette tip extension. In an advantageous embodiment, one or more spacer elements are arranged such that a continuous fluid aspiration area is created along the inner side of the pipette tip extension, meaning that, preferably, no isolating channels are created, but rather each created fluid aspiration area is fluidly connected to the other fluid aspiration areas. This ensures that the homogeneity of the liquid moving through the sample is maintained between the pipette tip and the pipette tip extension.

[0078] Although the constriction element is not mandatory for controlled insertion of the pipette tip into the pipette tip extension, it serves as an additional protection to ensure a repeatable flow field (repeatable gap height) above the sample, because the insertion depth can be individually controlled by the force applied during insertion. This is to prevent variations in the gap height caused by factors such as geometric tolerances in the manufacture of the pipette tip extension or the pipette tip, or by variations in the surface properties of individual tissues.

[0079] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), both the pipette tip extension and the pipette tip each include at least one spacer element. The spacer elements(s) of the pipette tip extension and the spacer elements(s) of the pipette tip tip are preferably adapted to each other such that, in the assembled state, the functionality is equal to an assembly including the pipette tip extension (which includes all spacer elements) and / or an assembly including the pipette tip (which includes all spacer elements).

[0080] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the assembly further includes a carrier for storing and / or holding one or more of the said pipette tip extensions. The carrier includes one or more receiving portions, each receiving portion being formed for storing and / or holding at least one pipette tip extension.

[0081] At least one receiving portion of the carrier may include a stop that is abutted against by the distal end of a suction tip when a suction tip is inserted into a suction tip extension stored in the receiving portion. The stop functions as a constriction element that extends through a dispensing orifice into the lumen of the suction tip extension when the extension is stored and / or held in the receiving portion, thereby defining a clearance height between the distal end of the inserted suction tip and the distal end of the suction tip extension. When the suction tip is inserted into the suction tip extension stored in the carrier, the suction tip abuts against the stop of the carrier in its final position, creating the defined clearance height above the dispensing orifice of the suction tip extension.

[0082] Another aspect of the invention relates to an insert for separating a pipette tip for aspirating and / or dispensing liquid and a pipette tip extension attached to the pipette tip. The insert includes one or more spacer elements sized to establish a fluid aspiration zone between the pipette tip and the attached pipette tip extension, the fluid aspiration zone being fluidly connected to the surrounding atmosphere at the proximal end of the attached pipette tip extension and to the lumen of the pipette tip adjacent to the distal end of the pipette tip. Similar to the spacer elements described above, one or more spacer elements are configured not to be circumferential; in other words, the spacer elements or combinations thereof do not cover the entire circumference of the inside of the pipette tip extension. They are intended to be spaced apart, but when the pipette tip extension is attached to the pipette tip, the pipette tip extension is opened proximally.

[0083] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the insert includes a connecting ring that holds one or more spacer elements, wherein the connecting ring includes a depth less than the depth of the spacer elements, or wherein the connecting ring is a base of the proximal end of a suction tip extension having a diameter greater than the receiving hole at the proximal end of the suction tip extension.

[0084] Another aspect of the invention relates to an assembly comprising a suction tube tip for inhaling and / or dispensing liquids, a suction tube tip extension, and one or more spacer elements.

[0085] The aspirator tip includes a proximal end, a distal end, and a circumferential outer wall that extends between the proximal and distal ends and tapers gradually toward the distal end. The outer wall has an outer side and an inner side and encloses an inner lumen defined by the inner side of the outer wall. The outer wall forms a proximal orifice at the proximal end for attachment to a suction device and a dispensing orifice at the distal end for aspirating and dispensing liquid.

[0086] The pipette tip extension includes a proximal end, a distal end, and an outer wall extending between the proximal and distal ends. The outer wall has an outer side and an inner side, and encloses an inner lumen defined by the inner side of the outer wall. The outer wall forms a receiving hole at the proximal end for inserting the pipette tip, and a dispensing hole at the distal end. The pipette tip extension is configured to attach to the distal end of a pipette tip.

[0087] One or more spacers are configured to separate the pipette tip from the attached pipette tip extension. The spacers are sized to create a fluid aspiration zone between the inner side of the outer wall of the pipette tip extension and the outer side of the outer wall of the pipette tip, the fluid aspiration zone extending from the dispensing orifice of the pipette tip extension to the receiving orifice of the pipette tip extension, and the fluid aspiration zone is in fluid communication with the surrounding atmosphere at the receiving orifice and with the lumen of the pipette tip adjacent to the distal orifice of the pipette tip.

[0088] The pipette tip, pipette tip extension, and one or more spacer elements may be constructed and combined with each other according to any of the previously described embodiments, unless there is a conflict. For example, in an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), in the embodiment described above, one or more spacer elements may be provided by a pipette tip extension, by a pipette tip, and / or by an insert.

[0089] For example, the insert includes one or more spacer elements. The insert can be configured to be inserted into the cavity of a pipette tip extension, for example, in a friction-fit manner, such that the spacer elements abut against the inner side of the outer wall of the pipette tip extension. Alternatively, the insert can be configured to attach to the outer wall of the pipette tip, such that the spacer elements abut against the outer side of the outer wall of the pipette tip. The insert is further configured to separate the pipette tip from the pipette tip extension, and to abut against the outer side of the outer wall of the pipette tip and the inner side of the outer wall of the pipette tip extension when the pipette tip is inserted into the pipette tip extension. By using the insert, when assembling the pipette tip, the pipette tip extension, and the insert, a fluid aspiration zone is created between the inner side of the pipette tip extension and the outer side of the pipette tip.

[0090] The insert according to the invention can be combined with any embodiment of the pipette tip extension and / or any embodiment of the pipette tip as previously described. The spacer element can be arranged exclusively in the insert or also in the pipette tip extension and / or the pipette tip.

[0091] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), one or more spacers are configured to provide a friction-fit attachment between the pipette tip extension and the distal end of the pipette tip. This friction-fit attachment can be achieved, for example, by adjusting the size of the spacers used, and / or by the number of spacers provided, and / or by the arrangement of one or more spacers between the outer side of the pipette tip and the inner side of the pipette tip extension.

[0092] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the assembly is configured to provide continuous fluid connection between the inner cavity of the suction tip, the inner cavity of the suction tip extension, and the surrounding atmosphere at the receiving port of the suction tip extension, via the distal orifice of the suction tip. Thus, the inner cavity of the suction tip extension not occupied by the inserted suction tip forms a first fluid reservoir, and the inner cavity of the suction tip forms a second fluid reservoir, which are fluidly connected to each other.

[0093] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the assembly includes a constriction element for controlling the insertion depth of a pipette tip within a pipette tip extension, the constriction element defining a gap height between the distal end of the inserted pipette tip and the distal end of the pipette tip extension. As described above, the constriction element may be provided by the pipette tip extension, by one or more spacers, and / or by the pipette tip itself.

[0094] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the assembly may be constructed as an integrally formed workpiece or as a workpiece formed of multiple parts, which are assembled, for example, prior to the use of the assembly.

[0095] When the assembly is constructed as a single integral workpiece, the assembly can be produced, for example, by injection molding as a single workpiece, or the assembly can be produced as multiple parts, which are connected to each other, for example, by gluing or welding. When the assembly is formed from multiple parts, the different parts are produced separately and assembled for use, for example, on a laboratory workbench or another workbench. This has the advantage that the assembly can be assembled prior to the desired embodiment.

[0096] Another aspect of the invention relates to a method of using a pipette tip extension. The method includes the steps of: providing a pipette tip extension, as described above, comprising one or more spacer elements; also providing a pipette tip, to which the pipette tip extension is fitted; for sample processing, liquid is drawn into the pipette tip; when the pipette tip is filled with liquid, the pipette tip is inserted into the pipette tip extension, but it is also possible to first insert the pipette tip into the pipette tip extension and then draw liquid using the assembly; the pipette tip extension is then placed on the sample with its distal end, and the distal end of the pipette tip extension is used to isolate an area of ​​the sample from the remaining area. A sealing effect can be achieved, for example, by adjusting the pressure at which the pipette tip extension is positioned on the sample or the corresponding surface on which the sample is located, and / or by providing a sealing material at the distal end of the pipette tip extension.

[0097] The method further includes the steps of dispensing liquid from a pipette tip, thereby generating liquid flow in the inner cavity of a pipette tip extension through a sample isolation zone from the pipette tip to a fluid aspiration zone of the pipette tip extension, the fluid aspiration zone being defined by the outer side of the outer wall of the pipette tip extension and the spacer element, by the outer side of the inserted pipette tip and by a flat surface below the dispensing opening.

[0098] Another step is to draw the liquid back into the pipette tip, thereby generating liquid flow in the opposite direction through the sample's isolation zone.

[0099] The method can be performed using a pipette tip extension comprising one or more spacers and a publicly available disposable pipette tip. Alternatively, the method can be performed using an assembly comprising a pipette tip extension, spacer elements, and a pipette tip configured or combined as described above.

[0100] Another aspect of the present invention relates to a method for treating an isolation zone of a sample using a liquid.

[0101] The method includes the following steps: - An isolation zone for the sample is generated by means of a first fluid reservoir, the first fluid reservoir encapsulates the distal end of a second fluid reservoir, and the isolation zone of the sample is sealed relative to the rest of the sample. - Connect the isolation zone of the sample to the second fluid reservoir in a fluid manner; - Distributing fluid from the second fluid reservoir to the first fluid reservoir, thereby generating fluid flow on the sample in the isolation zone along a first direction; and - Fluid is drawn from the first fluid reservoir into the second fluid reservoir, thereby generating fluid flow on the sample in the isolation zone along the second direction.

[0102] This method provides for the processing of a sample within an isolated zone, while allowing for the reuse of the same fluid. This enables locally defined and restricted processing of a limited volume of fluid. For example, when collecting a specific portion of a sample from a liquid, this method achieves this localized, specific processing, collection, and enhancement of such a portion within a defined volume of fluid. Providing two fluid reservoirs while guiding the fluid through the isolated zone of the sample allows for the repeated collection of sample portions within the same fluid volume, enabling enhancement to occur, wherein the fluid can move back and forth (which will be understood as bidirectional movement in this context) at least once between the two fluid reservoirs.

[0103] In this method, it is possible to dispense the full volume of fluid from the second fluid reservoir to allow the full volume of fluid to contact the isolation zone of the sample. However, it is also possible to retain a portion of the fluid volume in the second fluid reservoir, particularly when the liquid is used as the fluid, for example, to prevent air from the pipette tip from being drawn onto the sample.

[0104] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the method includes one or more of the following steps after fluid is distributed from the second fluid reservoir to the first fluid reservoir: - Immerse the isolation zone of the sample in a fluid for a certain period of time, such that during immersion, the fluid contacts the isolation zone of the sample without applying fluid flow; and / or - Continuous aspiration and dispensing of fluid between the second and first fluid reservoirs, thereby exposing the sample's isolation zone to repeated bidirectional fluid flow; and / or - subjecting the isolated area of ​​the sample to temperature treatment, especially to heating and / or cooling steps using heating and / or cooling devices that come into operational contact with the sample, thereby allowing the fluid to be adapted to the sample temperature.

[0105] A soaking step can be particularly suitable when culturing samples for a certain period of time using the fluids employed. For example, a soaking step can be suitable when performing a cell lysis reaction on a sample using a cell lysis reagent.

[0106] Any soaking time may be suitable, depending on the assay and / or sample requirements. For example, if procedural economy is of concern, the soaking time may not exceed 10 minutes. The soaking step can be applied after dispensing the full volume of fluid from the pipette tip or after dispensing only a portion of the fluid volume.

[0107] The continuous aspiration and dispensing of fluid between the second and first fluid reservoirs causes repeated exposure of the sample's isolation zone to bidirectional fluid flow. This allows for enhanced interaction between the fluid and the sample's isolation zone, and thereby may, for example, help increase the yield of components from the sample collected using the fluid, or increase the yield of the collected sample itself. The number of repetitions can be selected, for example, depending on the conditions or assay protocol.

[0108] Exposing the isolated area of ​​the sample to temperature allows the fluid to be adapted to the sample's temperature. This can be particularly desirable when, for example, the sample is a frozen and formalin-fixed paraffin-embedded tissue section and nucleic acid extraction should be performed on this sample. In this case, it may be necessary to raise the tissue temperature above the melting point of paraffin, which is approximately 56°C for typical histopathological paraffin. However, as an alternative or supplement, the fluid can be adjusted for temperature.

[0109] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the method includes one or more of the following steps after fluid is drawn from a first fluid reservoir into a second fluid reservoir: - A second isolation zone for the sample is generated using a first fluid reservoir, the first fluid reservoir continuously encapsulating the distal end of a second fluid reservoir, and the second fluid reservoir further comprising fluid, the sample being the same sample or another sample, and a second isolation zone for processing the sample as previously described; and / or - The third fluid reservoir exchanges with the first fluid reservoir; the third fluid reservoir differs in construction from the first fluid reservoir in terms of the size of the area isolated and sealed relative to the rest of the sample, and / or in terms of the volume of fluid that can be distributed from the second fluid reservoir to the first or third fluid reservoir; and bidirectional fluid flow is applied to the second isolation zone of the sample as previously described; and / or - Discard the first fluid reservoir from the second fluid reservoir; and / or - Distribute the fluid from the second fluid reservoir to the fluid container for further processing.

[0110] When a second isolation zone is generated and this zone is treated at least once using a two-way fluid as described above, further enhancement of the sample or sample components can be achieved when the same fluid is used. This can be particularly advantageous when, for example, the component to be collected and / or isolated is generally present in small quantities and a sample of the same type is available.

[0111] As a supplement or alternative, it may be possible to use the same liquid to treat the second isolation zone, but for a different size of region of interest. This can be achieved by exchanging the first fluid reservoir with a third fluid reservoir that differs in size regarding the isolated region. The size can be reduced or increased, or different shapes can be applied. This step allows for the collection of samples or components from the entire larger region of interest or from regions of interest with shapes that would otherwise be difficult to resolve.

[0112] When it is required or desired that the second fluid reservoir is not located at the first fluid reservoir at a remote location, the step of discarding the first fluid reservoir from the second fluid reservoir can be performed at any time. The same applies to any third or other fluid reservoir attached to the second fluid reservoir.

[0113] The step of distributing fluid from the second fluid reservoir to the fluid container makes the fluid available for any other subsequent processing steps. The fluid container can be any type of container used for fluids, such as containers for liquids that are part of laboratory equipment, such as tubes, microplates, etc.

[0114] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), fluid distribution and / or fluid intake are performed using the total volume of fluid present in the second reservoir and / or using a portion of the volume of fluid present in the second reservoir. As mentioned above, moving only a portion of the fluid volume can be advantageous to avoid air intake.

[0115] In embodiments of the invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), the sample is selected from a combination of the following: - Tissue, preferably tissue prepared for tissue analysis; - Tissue sections, preferably provided on a surface (e.g., the surface of a microscope slide); - Cell or cell culture includes bacterial cells, fungal cells, plant cells, animal cells, and / or human cells, etc.; and - One or more components of tissue, tissue section, cells and / or cell culture.

[0116] Tissue may be, for example, tissue isolated from the sample organism, which has been treated, for example, by formalin fixation, fixation with glutaraldehyde, cryopreservation, or alcohol fixation, or other available fixation methods, to preserve the structure and composition of the tissue for later analysis (e.g., histopathological analysis). Tissue may also be a portion of a tissue that should undergo further analysis. Tissue or a portion of a tissue may be provided in an embedding medium (e.g., paraffin). Tissue may be further provided on a carrier (e.g., on a microscope slide or other components required for subsequent preparation, such as tissue sections). Tissue may be isolated from microorganisms, plants, animals, or humans.

[0117] Tissue sections are sections of tissue of interest, including specific cell types or cellular contexts. They are typically generated from isolated tissue (including organic tissue with or without cancer cells), such as from a patient probe. Typical tissue sections range in thickness from 5 μm to 30 μm. Thinner or thicker sections are possible, and thicker sections may also be considered part of the tissue. Tissue sections are usually provided in an embedding medium (e.g., paraffin) or a medium for cryocutting, and are preferably preserved by a fixation step prior to section preparation. However, tissue can also be directly frozen without a fixation step.

[0118] The cells can be any prokaryotic or eukaryotic cell that should be analyzed. These can be, for example, bacterial cells, including primitive bacterial cells. By way of example, bacterial cells can be *E. coli* cells or other cells involved in standard laboratory tests or other bacterial cells involved in diseases, for example. Cells can also be fungal cells, such as *Saccharomyces cerevisiae* cells. Cells can also be derived from another eukaryotic organism, such as a plant, animal, or human.

[0119] Cell culture of sample cells is the culture of cells or cell populations in or above a culture medium or nutrient solution outside an organism. Cell culture media are tailored to the requirements of the cells being cultured and the laboratory requirements. For example, bacterial cells can be cultured in semi-solid or solid cell culture media in the form of so-called agar plates. Cell culture in liquid media is also known, and this is commonly used for animal or human cell culture. The cells used in cell culture can be primary cells (generated directly from an organism) or cell lines (immortalized cells).

[0120] The components of tissues, tissue sections, cells and / or cell cultures may be, for example, proteins, nucleic acids, carbohydrates, components containing fatty acids, vitamins, hormones, other components of cells and / or combinations thereof.

[0121] In embodiments of the present invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), The fluid is a liquid selected from a combination of the following: - Buffer or cell culture medium used for culturing and / or maintaining and / or storing one or more samples; - A reagent used to process a sample, preferably for performing cell lysis, staining, binding reactions, or for removing embedding agents.

[0122] Cell culture medium is a medium suitable for short-term or long-term culture of cells or cell populations.

[0123] A buffer is a reagent that contains a pH-stabilizing component, such as a salt solution. Examples include HEPES (hydroxyethylpiperazine ethanesulfonic acid) buffer, sodium dihydrogen phosphate buffer, or TRIS-based (tris(hydroxymethyl)aminomethane) buffer.

[0124] Reagents used to perform cell lysis reactions include, for example, proteinase K, Quick Extract FFPE DNA Extraction Solution (from the Illumina Quick Extract FFPE DNA Extraction Kit), or direct reagents from the Ion AmpliSeq DirectFFPE DANN Kit.

[0125] The reagents used for staining reactions can be any reagent used to stain organs, cell types, or their components. Established staining techniques include, for example, immunohistostaining using antibodies, reagents for inserting nucleic acids (e.g., ethidium bromide), or other staining agents for detecting, for example, basophilic, eosinophilic, or neuphilic structures.

[0126] Reagents used to perform the binding reaction may include, for example, antibodies and / or magnetic beads.

[0127] The reagent used to remove embedding agents (e.g., for removing paraffin embeddings) can be an organic solvent, such as xylene, mineral oil, or cyclohexylamine.

[0128] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the sample is a tissue section provided on a microscope slide, and the fluid is a liquid used to perform a cell lysis reaction and to collect one or more components of a tissue section selected from a combination of the following: - Nucleic acid; -protein; - Including components such as carbohydrates, fatty acids, vitamins and / or hormones or other cellular compounds; and / or - A combination of the above items.

[0129] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the tissue section is a formalin-fixed, paraffin-embedded tissue section from a biopsy or from a resected tumor.

[0130] In embodiments of the present invention (which may be combined with any other embodiments mentioned or to be mentioned, unless there is a conflict), one or more steps in the method steps are performed manually or automatically using a liquid handling workstation using a suction tube.

[0131] The pipette is a handheld pipette designed for manual use by laboratory personnel. The advantage of manual use is that the procedure can be performed using methods that are individually selected and tailored to the specific situation.

[0132] The advantage of automating this method using a liquid handling workstation is that large numbers of samples can be processed in a precise manner with consistent quality and specificity. A liquid handling workstation is typically controlled by one or more controllers, such as a suction robot, the liquid used, the suction, dispensing, mixing, or other suction steps, the movement of the suction tubing, containers, etc.

[0133] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict): - The first fluid reservoir is provided by a pipette tip extension configured to attach to the distal end of a pipette tip. The pipette tip extension includes a proximal end, a distal end, and an outer wall extending between the proximal and distal ends. The outer wall forms a receiving hole at the proximal end for inserting the pipette tip and a dispensing hole at the distal end. - The second fluid reservoir is provided by a suction nozzle for dispensing and / or drawing in liquid; The suction tube tip is attached to the suction tube tip by inserting the distal end of the suction tube tip into the suction tube tip extension through the receiving hole of the suction tube tip extension; and The fluid connection between the suction tip extension and the suction tip is formed by means of at least one spacer element that separates the suction tip from the suction tip extension.

[0134] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), a suction tip, a suction tip extension, and at least one spacer element form a functional assembly, which is formed by multiple parts or as a single workpiece.

[0135] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), at least one spacer element is sized to establish a fluid aspiration region between the inner side of the outer wall of the pipette tip extension and the outer side of the outer wall of the pipette tip, the fluid aspiration region extending from the dispensing orifice of the pipette tip extension to the receiving orifice of the pipette tip extension, and the fluid aspiration region is in fluid communication with the surrounding atmosphere at the receiving orifice and with the inner cavity of the pipette tip adjacent to the distal orifice of the pipette tip.

[0136] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), at least one contraction element is provided by means of the following: - Pipe tip extension; and / or - Pipette tips; and / or - Independent insert.

[0137] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), at least one spacer element is configured to provide a friction-fit attachment between the suction tip extension and the distal end of the suction tip.

[0138] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), the pipette tip is selected from a combination of disposable pipette tips and fixed pipette tips.

[0139] In an embodiment of the invention (which may be combined with any other embodiment mentioned or to be mentioned, unless there is a conflict), a pipette tip, a pipette tip extension, and at least one spacer element form an assembly including at least one constriction element for controlling the insertion depth of the pipette tip within the pipette tip extension, the constriction element defining a gap height between the distal end of the inserted pipette tip and the distal end of the pipette tip extension.

[0140] The methods described above are particularly suitable for use in any of the embodiments described herein with one of the pipette tip extensions described herein, together with the pipette tip in the embodiments described herein and at least one spacer element described herein, to perform the construction of the pipette tip extension, the pipette tip and (one or more) spacer elements that can be adapted to each other to form the assembly described herein. Attached Figure Description

[0141] Embodiments of the invention will now be described in more detail with reference to the accompanying drawings. These are for illustrative purposes only and are not intended to be limiting. The drawings show: Figure 1AA schematic three-dimensional side view of the suction tube tip extension is shown, in which the view of the three spacer elements near the receiving hole and configured as an inner rod is particularly visible; Figure 1B Show Figure 1A A schematic diagram of the proximal end of a pipette tip extension, showing what is being used as... Figure 1C and Figure 1D The intersecting planes of the base of the sectional view shown; Figure 1C This shows the intersecting plane C-C. Figure 1A A schematic cross-sectional view of a suction tube tip extension, including a front view of a stop surface with an inner rod; Figure 1D This shows the intersecting plane D-D. Figure 1A A schematic cross-sectional view of a suction tube tip extension, showing an inner rod selected through the cross section and an inner rod shown in the side view. Figure 2A A schematic diagram of the proximal end of an embodiment of a suction tube tip extension including a spacer element configured as a rod is shown, wherein the inner rod is arranged flush with the proximal end; Figure 2B A schematic diagram of the proximal end of another embodiment of a suction tube tip extension including a spacer element configured as a rod is shown, wherein the inner rod is arranged offset relative to the proximal end; Figure 3A A schematic diagram showing the distal end of an embodiment of a suction tube tip extension is provided, wherein the distal end of the suction tube tip extension includes a dispensing hole and an inner rod extending to the distal end and forming a constriction element therein as a spacer element. Figure 3B Show Figure 3A A schematic diagram of the distal end of the suction tip extension of a suction tube; Figure 4A A schematic diagram of the distal end of another embodiment of a suction tube tip extension is shown, the distal end including a dispensing hole and a sieve-like support rod forming a constriction element; Figure 4B Show Figure 4A A top view schematic diagram of the distal end of the suction tube tip extension; Figure 5A A schematic three-dimensional side view of an assembly is shown, which includes a pipette tip extension, a pipette tip, and a spacer element, wherein the pipette tip extension includes a spacer element; Figure 5B Show Figure 5A A schematic sectional view of the assembly; Figure 5C A schematic three-dimensional side view of an embodiment of the assembly is shown, wherein the suction tip includes a spacer element; Figure 5DA schematic three-dimensional side view of the components, illustrating another embodiment of the assembly, wherein the spacer elements are provided by separate inserts; Figure 6A A schematic diagram showing the distal end of an embodiment of a pipette tip extension is provided, wherein the spacer element is used as a constriction element for controlling the insertion depth of the pipette tip. Figure 6B A schematic diagram of an embodiment of a suction pipette tip extension is shown, wherein a suction pipette tip is inserted into the suction pipette tip extension, and wherein a constriction element is provided by a carrier; Figure 6C A schematic diagram of an exemplary embodiment is shown, in which the pipette tip includes a constriction element; Figure 6D A schematic diagram of an embodiment of a multi-part suction tube tip extension is shown, wherein a second lower portion provides a constriction element.

[0142] Figure 6E Showing the assembly status Figure 6C Suction tube tip extension; Figure 7 Two identical pipette tip extensions are shown in an embodiment having a dispensing orifice and each having an inserted disposable pipette tip. The left pipette tip extension is not yet filled with fluid, while the right pipette tip extension is operatively connected to a liquid handling workstation and is filled with fluid after being placed on a surface providing a sample slice and after fluid has been dispensed from the disposable pipette tip. Figure 8 Two identical pipette tip extensions are shown in another embodiment, having a dispensing orifice, a sieve-like constriction element, and an inserted disposable pipette tip. The left pipette tip extension is not yet filled with fluid, while the right pipette tip extension is operatively connected to a liquid handling workstation and is filled with fluid after being placed on a surface providing a sample slice and after fluid has been dispensed from the disposable pipette tip. Figure 9 Microscopic images of tissue sections fixed on a microscope slide are shown, in which four regions of interest are specially treated using a pipette tip extension according to the invention, and magnified images are shown showing two treated regions (dissolved areas) surrounded by untreated tissue. Figure 10 A schematic diagram of an embodiment of a pipette tip extension is shown. The pipette tip extension includes a spacer element and an inserted pipette tip, which is a reusable pipette tip. Figure 11A -D shows a schematic diagram of the proximal end of various embodiments of the pipette tip extension, illustrating different variations in shape and different possible positions of the pipette tip receiving area and the fluid aspiration area; Figure 12A - I shows a schematic diagram of the dispensing hole of various embodiments of the suction tube tip extension, illustrating different variations in the shape of the dispensing hole; Figure 13A -C shows a schematic diagram of various embodiments of the suction tube tip extension, showing the inner side of the outer wall; Figure 14 A schematic cross-sectional view showing an embodiment of a pipette tip extension configured to receive two pipette tips for sample processing; Figure 15 A schematic outline of a demonstration method for treating samples using liquids is shown; Figure 16 A schematic diagram illustrating the method steps for processing samples; Figure 17 A schematic diagram illustrating other specified method steps for processing the sample; and Figure 18 A diagram illustrating other specified additional and optional method steps is provided. Detailed Implementation

[0143] Figures 1A to 1D A schematic diagram illustrates an exemplary embodiment of a suction tube tip extension 1. The suction tube tip extension 1 includes a proximal end 2 and a distal end 3. An outer wall 4 extends between the proximal end 2 and the distal end 3. The outer wall 4, including an outer side 5 and an inner side 6, encloses an inner cavity 7. A central axis 11 extends longitudinally from the proximal end 2 toward the distal end 3. Therefore, when viewed in a direction orthogonal to and opposite to the central axis, the inner cavity 7 is defined by the inner side 6 of the outer wall 4.

[0144] At the proximal end 2, an outer wall 4 forms a receiving hole 8, and at the distal end 3, an outer wall 4 forms a dispensing hole 14. As shown in the following figures, the receiving hole 8 is configured to receive the suction tip 12 when the suction tip extension 1 is to be attached to the suction tip 12. When the suction tip 12 is introduced into the suction tip extension 1 in the end position, the diameter of the receiving hole 8 is particularly larger than the diameter of the suction tip 12 at the same height. Therefore, the outer side of the suction tip 12 does not contact the inner side 6 of the outer wall 4 of the suction tip extension 1, which instead includes one or more spacer elements 9 that provide a base for the suction tip 12 within the suction tip extension 1, in which the outer side of the suction tip 12 is separated from the inner side 6 of the suction tip extension 1. Although it is possible that the pipette tip 12 contacts the inner side 6 of the pipette tip extension at one contact point, the remaining outer side of the pipette tip 12 is separated from the inner side 6 of the pipette tip extension by one or more spacers 9. Also for Figures 11A to 11D Explain the possible bases.

[0145] Figure 1AThe image shows a three-dimensional side view of a suction tube tip extension 1. This view specifically shows the proximal end 2 with the receiving hole 8. The suction tube tip extension 1 shown in this example includes three spacer elements 9. Each spacer element 9 is configured as an extension rod, which is a protrusion from the outer wall 4 into the inner cavity 7, projecting towards the central axis 11 in this example. In the illustrated embodiment, each rod is arranged flush with the proximal end 2 and extends continuously from the proximal end 2 of the suction tube tip extension 1 almost all the way to the distal end 3 (see [reference]). Figure 1C and Figure 1D ).

[0146] In this configuration, each of the three rods includes a stop surface 10. This stop surface 10, in this example, is the surface of the rod facing the central axis 11 of the suction tip extension 1. The size of the stop surface 10 is determined by the shape and dimensions of the spacer element, which in the case of the rod are length, depth, and width (see example...). Figure 13C The stop surface 10 can be abutted by the suction tip, and a safety base for the suction tip 12 is provided within the suction tip extension 1.

[0147] The illustrated pipette tip extension 1 includes a proximal portion in which a hollow cylinder is formed on the outer wall 4, while in the middle and distal portions, the outer wall 4 gradually tapers towards the distal end 3. The dimensions of the extension rods are adapted to the shape of the pipette tip extension 1 given by the shape of the outer wall 4, such that the stop surface 10 of each rod extends parallel to the inner side 6 of the outer wall 4. Figure 1D ).

[0148] Figure 1B Showing the Figure 1A A schematic diagram of the proximal end 2 of the suction tube tip extension. The spacer element 9, in this example a rod, is formed as part of the outer wall 4 in this embodiment. However, as will be discussed below, the spacer element 9 may be provided as a separate insert 16 or as part of the suction tube tip 12 to be inserted. Figure 1B In the illustrated embodiment, spacer elements 9 extend from the proximal end 2 toward the distal end 3. For each spacer element 9, an edge extending from the proximal end 2 to the surface facing the lumen 7 and the central axis 11 is also shown. From this view, the development of this surface toward the dispensing orifice 14 is also visible. Since this surface will be abutted against by the suction tip 12 and provides a stop, this surface is also referred to as the stop surface 10, wherein the stop prevents the suction tip 12 from being further inserted into the suction tip extension 1. Viewed from above, the distal ends of the three spacer bars are inserted into the dispensing orifice 14. Figure 1C and Figure 1D The intersecting planes of the base of the sectional view are indicated.

[0149] Figure 1C Showing based on Figure 1BA schematic cross-sectional view of the intersecting plane C-C shown. This figure illustrates the intersection of the two planes. Figure 1A A longitudinal section of the suction tip extension 1, showing a front view of one of the rods serving as spacer elements 9. In that view, the stop surface 10 of the rod is visible, and the inner rod is shown to extend almost the entire length of the suction tip extension 1, beginning flush with the proximal end. However, the inner rod does not extend all the way to the distal end 3 of the suction tip extension, but leaves a gap with a height h to the distal end 3. The distal end 3 of this suction tip extension 1... Figure 6A It is shown at a higher magnification, where the gap height h is also shown.

[0150] Figure 1D Showing based on Figure 1B A schematic cross-sectional view of the intersecting planes D-D shown. This figure illustrates the intersection of... Figure 1A A longitudinal section of the suction tube tip extension 1, wherein a front view of one of the rods is cut (left), and one of the rods is shown in a side view.

[0151] Figure 2A schematically shown with Figure 1A The embodiment of the proximal end 2 of the pipette tip extension shown basically corresponds to the proximal end 2 of the pipette tip extension 1, wherein three spacer elements 9 are arranged flush with the proximal end 2.

[0152] Figure 2B The proximal end 2 of a suction tip extension 1 in another embodiment is schematically shown. The suction tip extension 1 also includes three spacer elements 9, which are configured as extension rods in this embodiment. In the illustrated embodiment, the rods are offset from the distal end 3 of the suction tip extension 1. In other words, the proximal end of each rod is separated from the proximal end 2 of the suction tip extension 1. The spacer elements 9 may be integrally formed with the outer wall 4, or they may be separate pieces attached to the inner side 6 of the outer wall 4.

[0153] Figure 3A The proximal end 3 of the suction tip extension 1 is schematically shown in a partial longitudinal section at a higher magnification. The spacer element 9 visible in this section is constructed as an extension rod. The surface of the rod against which the suction tip 12 rests when the suction tip extension 1 is attached to the suction tip 12 is also fully visible in the front view. This surface is called the stop surface 10 because it restricts the position of the suction tip 12 relative to the inner side 6 of the suction tip extension 1 when the suction tip 12 is moved into the suction tip extension 1.

[0154] The rod extends toward the dispensing hole 14, but is offset from the distal end 3. The length of the offset of the distal end 3 corresponds to the gap height h, which is generated when the suction tip 12 is inserted into the suction tip extension 1 and when the distal end 30 of the suction tip 12 is positioned flush with the distal end of the spacer element 9 (see [link]). Figure 6A In this case, the distal end of the spacer element 9 generates the minimum possible lateral extension l1 of the lumen, and thereby restricts further insertion toward the distal end 3 of the suction tip extension 1, wherein the distal end of the suction tip can no longer pass through the minimum possible lateral extension l1 of the lumen during the insertion process.

[0155] However, the constriction function may not necessarily be provided by the spacer(s) at the distal end of the spacer(s), but rather at a position slightly closer to the proximal end 2. The force used to press the suction tip 12 against the distal end 2 of the suction tip extension also affects the insertion depth and the resulting gap height h, because a sufficiently large insertion force can push the distal end 30 of the suction tip 12 out of the constriction region when the constriction element allows for slight deformation when pressure is applied.

[0156] The distal end 3 of the pipette tip extension 1 includes a sealing portion 15 that seals the dispensing orifice 14 when the distal end 3 is pressed against the surface of the sample being provided or into the prepared sample. The sealing portion 15 may simply be the furthest part of the pipette tip extension that contacts the surface or the prepared sample. When the distal end 3 of the pipette tip extension 1 contacts, for example, a rigid surface (e.g., the surface of a microscope slide), a seal may be facilitated, for example, by slight deformation of the material at the furthest end. The distal end 3 of the pipette tip extension 1 may, for example, penetrate the tissue of a tissue section until it abuts against the rigid surface of the microscope slide. However, the seal need not be 100%; for example, surrounding tissue may also provide a "seal" such that it may be sufficient for the distal end 3 of the pipette tip extension 1 to be pressed into the biological sample (especially the prepared sample) to a sufficient depth.

[0157] like Figure 3A The size of the sealing portion 15 shown is also affected in this example by the geometry of the distal end 3 of the suction tip extension 1. In this example, an inclined segment adjacent to the sealing portion 15 shown is used.

[0158] Figure 3B schematically showing the Figure 3A The view shown is of the distal end 3 of the pipette tip extension 1, which has three spacer elements 9. In this view, the three spacer elements can be seen inserted into the dispensing hole 14, and different sections of the pipette tip with different inclined surfaces can be seen.

[0159] Figure 4A Another embodiment of the distal end 3 of the suction tube tip extension 1 is illustrated schematically. In this case, the distal end 3 includes a sieve-like support rod 16 above the dispensing hole 14, which forms a constriction element 13. A front view of the stop surface 10 of the extension spacer element 9 is also shown. Figure 4B schematically shown Figure 4A The view of the far end 3.

[0160] The support rods extend laterally relative to the central axis 11 of the suction tip extension 1. In the illustrated embodiment, they form a fluid-permeable sieve-like structure at their distal ends. The support rods 16 serve as a constriction portion, which prevents the suction tip 12 from being further inserted toward the distal end 3 of the suction tip extension 1 and creates a gap between the distal end 30 of the suction tip 12 and the distal end 3 of the suction tip extension 1. The sieve-like arrangement ensures that liquid dispensed from the suction tip 12 can still flow into the gap created above the dispensing orifice 14.

[0161] Figure 5A A schematic three-dimensional side view of the assembly is shown, which includes a suction tip extension 1, a suction tip 12, and a spacer element 9. In the illustrated embodiment, the spacer element 9 is provided by the suction tip extension 1. The suction tip extension 1 is attached to the distal end 30 of the suction tip 12. The suction tip 12 used in this example is a disposable suction tip 12, which includes a reinforcing bar (known in the art) in its proximal section 35 to provide a stabilizing effect when the disposable suction tip 12 is attached to, for example, the suction tube 22 of a liquid handling workstation 25.

[0162] The pipette tip extension 1 used corresponds to Figures 1A to 1D The described pipette tip extension includes three spacer elements 9 configured as rods that extend continuously from the proximal end 2 to the distal end 2 of the pipette tip extension 1, ending at an offset relative to the distal end 3. The surface of each extension rod facing the central axis 11 serves as a stop surface 10 for the inserted pipette tip 12; all stop surfaces 10 collectively form a “common” stop surface of the pipette tip extension 1, defining the position of the pipette tip 12 within the pipette tip extension 1.

[0163] The spacer element 9 maintains a portion of the inner cavity 7 of the pipette tip extension 1. These portions serve as fluid aspiration zones, which can be filled with fluid or liquid from the pipette tip 12 when the dispensing orifice 14 of the pipette tip extension 1 is closed. In this embodiment of the pipette tip extension 1, the spacer element 9 further serves as a component for constricting the insertion of the pipette tip 12 within the pipette tip extension 1. This ensures a gap is formed between the distal end 30 of the pipette tip 12 and the distal end of the pipette tip extension 1. Subsequently, when the dispensing orifice 14 of the pipette tip extension 1 is closed by placing its distal end 3 against a suitable surface, liquid from the pipette tip 12 can move through the gap into the remaining cavity between the pipette tip 12 and the pipette tip extension 1.

[0164] Figure 5B Is it through Figure 5A The assembly shown is a schematic cross-sectional view based on the cross-sectional plane A-A as shown. The spacer on the right is shown in the cross-sectional view, while a portion of the fluid aspiration zone 31 is visible on the left. The flow path from the inner cavity 38 of the suction tip 12 to the portion of the inner cavity 7 of the suction tip extension 1 that is not occupied by the suction tip 12 through the gap between the distal end 30 of the suction tip 12 and the distal end 3 of the suction tip extension 1 is particularly visible here. This unoccupied portion of the inner cavity 7, together with the gap, forms the fluid aspiration zone 31.

[0165] The fluid aspiration zone 31 is fluidly connected to the lumen 38 of the aspiration tip 12 via the distal end 30 of the aspiration tip 12, and also fluidly connected to the surrounding atmosphere at the proximal end 2 of the aspiration tip extension 1. This ensures that when the assembly is placed on the surface 19 and the dispensing orifice 14 of the aspiration tip extension is closed by the surface and / or tissue placed on it, the liquid 20 can move between the lumen 38 of the aspiration tip 12 and the lumen 7 of the aspiration tip extension. This also ensures continuous contact of the continuously moving liquid 20 with the surface, or, if tissue or tissue sections are placed thereon, continuous contact with the tissue. See also Figure 7 and Figure 8 Depending on the liquid 20 used, a reaction may occur on the surface or tissue in a very restricted area below the dispensing orifice 14 of the pipette tip extension 1, and as... Figure 9 As described in the context.

[0166] Figure 5CAn alternative embodiment of the three components of the assembly is shown in a three-dimensional view. Here, the aspirator tip 12 includes a spacer element 9. The disposable aspirator tip 12 shown in this example has a basic structure known in the art. The aspirator tip 12 includes: a proximal end 29 having a proximal orifice 33 for attachment to a suction tube; a distal end 30 having a distal orifice 34 serving as an inlet / outlet for the aspirated and / or dispensed liquid 20; and an outer wall 28 extending between the proximal end 29 and the distal end 30.

[0167] The aspirator tip 12 includes a reinforcing proximal section 35 at the proximal end 29 and surrounding the proximal end aperture 33. The reinforcement should prevent deformation of the aspirator tip 12 when attached to a suction tube for aspiration and / or dispensing via the proximal end aperture 33. The aspirator tip 12 here includes a circumferential thickening at the proximal end 29 for reinforcement, wherein the longitudinally thickened area is referred to as the proximal section 35. Other or additional reinforcing structures, such as reinforcing ribs, are also possible.

[0168] The segment adjacent to the proximal segment 35 with its reinforced structure is referred to herein as the intermediate segment 36, followed by the distal segment 37. The intermediate and distal segments 36 are segments of the suction tube tip 12 used to receive the aspirated liquid. Their geometry can be varied according to different requirements, such as the volume and / or type of liquid, or the requirements of the suction device used. The suction tube tip shown here tapers continuously from the intermediate segment 36 and distal segment 38 all the way to the distal end 30.

[0169] The suction tip 12 includes a plurality of spacer elements 9, which are configured as extension rods. Two rods are visible, extending from the proximal end 29 toward the distal end 30 of the suction tip 12. The spacer elements 9 are positioned on the outer side of the suction tip 12. Their position on the suction tip 12 is chosen such that when the suction tip extension 1 is attached to the distal end 30 of the suction tip 12, the spacer elements 9 are abutted against the inner side 6 of the suction tip extension 1, and a fluid aspiration zone 31 is established between the outer side of the suction tip 12 and the inner side of the suction tip extension 1.

[0170] In the illustrated embodiment, when the suction tip 12 is inserted into the suction tip extension 1, it may be sufficient for the spacer element 9 to inherently function as a stopper for the suction tip 12. In this case, the spacer element 9 is sized such that when the spacer element abuts against the inner side 6 of the suction tip extension 1, the suction tip 12 cannot be significantly pushed further into the suction tip extension 1. Therefore, the spacer element 9 is sized such that a frictional connection is created before the distal end 30 of the suction tip 12 reaches the distal end 3 of the suction tip extension 1, and such that a gap is allowed to be created between the distal end 30 of the suction tip 12 and the distal end of the suction tip extension 1 during assembly. An additional constriction element 13 as described herein may be provided as a supplement to or alternative to what is provided by the suction tip extension 1 and / or the suction tip 12.

[0171] Figure 5D A three-dimensional side view schematically illustrates a further alternative embodiment of the three components of the assembly. The assembly also includes a pipette tip extension 1, spacers 9, and a pipette tip 1. In this case, the spacers 9 are provided by an insert 17. This insert is adapted to be positioned between the pipette tip extension 1 and the pipette tip 12, and is configured to establish a fluid aspiration zone between the pipette tip 12 and the pipette tip extension 1 when assembled. The insert shown includes three spacers 9, which are connected here by connecting rings 39. In this case, the connecting rings 39 are positioned at the proximal end of the insert 17. The connecting rings 39 are further configured to be placed at the proximal end 2 of the pipette tip extension 1 while ensuring fluid connectivity between the spacers 9 and the surrounding atmosphere.

[0172] Figure 6A Shown at a higher magnification according to Figure 1A A schematic cross-sectional view of the distal end of the suction tip extension 1. In this embodiment, a spacer element 9 is provided by the suction tip extension 1 and serves as a constriction element 13 for controlling the insertion depth of the suction tip. The suction tip 12 is shown inserted into the suction tip extension 1. The outer side of the suction tip 12 abuts against the corresponding stop surface 10 of the spacer element 9. The spacer element 9 is configured to stop during insertion before the distal end 30 reaches the distal end 3 of the suction tip extension, thus creating a gap of height h. In this case, the spacer element 9—based on its dimensions—defines a minimum lateral extension l1 of the lumen 7 of the suction tip extension 1 in the region of the distal end 3. This minimum lateral extension l1 can constrict the insertion of the suction tip 12 alone or in combination with, for example, the dimensions of the rest of the spacer element(s).

[0173] Additionally, a lateral extension l2 of the dispensing orifice 14 is shown. This lateral extension l2 is essentially defined by the dimensions of the outer wall 4 of the distal end 3 of the suction tube tip extension 1. (As will be...) Figure 6C and Figure 6D As defined in the context, the size of the lateral extension l2 of the dispensing orifice can be varied. For example, it is possible to provide different pipette tip extensions 1 with varying standard dispensing orifices 14, or it may be possible to provide interchangeable distal ends 3 for the pipette tip extensions 1, and each of such interchangeable distal ends 3 may have a different dispensing orifice 14.

[0174] Figure 6B An assembly is shown, comprising a pipette tip extension 1 and a pipette tip 12 inserted into the pipette tip extension 1, wherein the pipette tip extension includes a spacer element 9. The pipette tip extension 1 is positioned within a receiving portion 24 of a carrier 18. The carrier 18 is configured to store one or more pipette tip extensions. In this example, the insertion depth of the pipette tip 12 is controlled by a constriction element 13 provided by the carrier 18.

[0175] Figure 6B An alternative embodiment of the aspirator tip extension 1, together with the inserted aspirator tip 12 and carrier 18, is illustrated schematically. The aspirator tip extension 1 includes spacer elements 9, two of which are visible in this cross-sectional view but are not cut off themselves, but are shown laterally from the front. In this embodiment, the spacer elements 9 extend less towards the distal end 3 of the aspirator tip extension 1 compared to the previously described embodiments. These spacer elements 9 are specifically configured to provide a secure base for the aspirator tip 12 within the aspirator tip extension 1 when the aspirator tip abuts against the spacer elements 9. Preferably, the base of the aspirator tip 12 within the aspirator tip extension 1 is provided by a friction-fit connection. It is not known that the spacer elements 9 provide a constriction function to adjust the insertion depth of the aspirator tip 12.

[0176] A suction tube tip extension 1 is shown inserted into the complementary receiving portion 24 of the carrier 18. Figure 6B The partial view shows two receiving portions 24. The carrier 18 is primarily constructed to store one or more pipette tip extensions 1. For this purpose, the carrier 18 includes one or more receiving portions 24, each adjusted in shape and size to receive one pipette tip extension 1. The pipette tip extension 1 inserted into the receiving portion 24 is presented by the carrier 18 in a manner that allows it to be automatically picked up, for example, by a pipette tip 12, which is connected to, for example, a pipette 22 of a liquid handling workstation 25. It is possible that a carrier 18 includes, for example, one or more rows of eight or twelve receiving portions 24.

[0177] The carrier 18 shown also includes a stop 23, which serves as a constriction element 13 to control the insertion depth of the suction tip 12 into the suction tip extension 1. In various cases, the stop 23 is positioned at the bottom of the receiving portion 24. Thus, in this embodiment, the constriction element 13 is provided by the carrier 18 and is configured as a protrusion that passes through the dispensing hole 14 of the suction tip extension 1 inserted into the corresponding receiving portion 24. The suction tip 12 begins to stop when the distal end 30 of the suction tip 12 inserted into the suction tip extension 1 of the corresponding receiving portion 24 abuts against the stop 23 of the carrier 18. This state is shown for the left receiving portion 24, while the right receiving portion 24 is shown free for a better overview of the stop 23. Thus, the stop 23 defines the end position of the suction tip 12 in terms of height. In the next step, the suction tip 12, together with the attached suction tip extension 1, is removed from the carrier 18, and the suction tip 12 remains in the end position because it is held there by friction.

[0178] Figure 6C Another exemplary embodiment is schematically illustrated in a three-dimensional side view, wherein the constriction element 13 is provided by the aspirator tip 12. In the illustrated embodiment, the aspirator tip includes a shoulder that serves as the constriction element 13 because it is configured to abut against the proximal end of the aspirator tip extension 1. The shoulder is not circumferential in a direction orthogonal to the z-direction / central axis of the aspirator tip 12 to allow pressure equalization as liquid 20 is moved between the aspirator tip 12 and the aspirator tip extension 1. The shoulder can be continuous circumferential if the proximal end 2 of the aspirator tip extension 1 has, for example, a discontinuous surface (e.g., a notched surface to allow air to escape). The shoulder can be a simple discrete protrusion of the outer wall 28 of the aspirator tip 12, or it can be configured as a rib. By way of example, a top view of the aspirator tip 12 including such a shoulder is shown above the side view. However, it is also possible that, for example, insert 17 includes a constriction element for limiting the insertion depth of the suction tube tip 12 when insert 17 is used to provide one or more spacer elements 9.

[0179] Figure 6D A schematic cross-sectional view of a suction tube tip extension 1 is shown, which is constructed in two parts: a first upper part 1.1 and a second lower part 1.2. In this embodiment, the first part 1.1 specifically includes a spacer element 9 and a receiving hole 8, while the second part 1.2, which is the lower part here, includes a dispensing hole 14 and a constriction element 13. In this case, the constriction element 13 is a thickening of the outer wall 4 in the distal region. Figure 6EAs shown, the inserted suction tip 12 abuts against the constriction element 13, and further insertion of the suction tip 12 is prevented. In this example, the second lower portion 1.2 is provided as an attachable element and can be replaced by another lower portion 1.2 (if this is required, for example, by a certain area of ​​concern), which includes, for example, another lateral extension or diameter l2 of the dispensing orifice 14.

[0180] Especially when comparing Figure 6C and Figure 6D The principle that the lower part 1.2 can be interchanged is evident when the pipette tip extension 1 is shown. Although the constriction element 13 remains the same in its structure, Figure 6D The lateral extension l2 of the dispensing hole 14 in the lower part 1.2 of the pipette tip extension 1 shown is significantly smaller than that of the pipette tip extension 1. Figure 6C The lateral extension l2 of the dispensing hole 14 of the suction tube tip extension 1 shown.

[0181] Figure 7 Two identical pipette tip extensions 1 are shown in a schematic overview diagram, each having a pipette tip 12 inserted into an inner cavity 7. In this embodiment, the pipette tip extension 1 includes at least three spacer elements 9 configured as extension rods. The rods are abutted against the inserted pipette tip 12 at their stop surfaces, which also at least partially limits the insertion depth of the pipette tip 12. A higher magnification view of the left-side assembly of the pipette tip extension 1 and the pipette tip 12 highlights the gap between the distal end 30 of the pipette tip and the distal end 3 of the pipette tip extension.

[0182] The corresponding assembly on the right is shown placed on the sample portion 21, which in this example is provided by the surface 19 of a microscope slide. The distal end 3 of the pipette tip extension 1 is substantially sealed to the surrounding atmosphere through the sample portion and / or surface 19, such that the resulting gap fluidly connects the inner cavity of the pipette tip 12 to the fluid aspiration zone 31 between the spacer element 9, the inner side 6 of the outer wall 4, and the outer side of the pipette tip 12. Liquid 20 is present in the fluid aspiration zone 31, including in the gap. Liquid 20 reaches above the proximal end of the spacer element 9 and is fluidly connected to the surrounding atmosphere at the proximal end 2 of the pipette tip extension 1. This open configuration allows movement of liquid between the pipette tip 12 and the pipette tip extension 1 when the dispensing orifice 14 of the pipette tip extension is sealed.

[0183] The suction tip 12 of the assembly is shown as a suction tube 22 attached to the liquid handling workstation 25. The suction tube 22 is a component of the suction head 27 of the liquid handling workstation 25, which is also under the control of the controller. In this case, the movement and friction-fit connection of the suction tip 12 to the suction tip extension 1, as well as the movement to the microscope slide, the positioning therein, and the suction steps (e.g., dispensing and / or aspiration steps) can be performed under the control of the liquid handling workstation 25.

[0184] Figure 8 Two identical pipette tip extensions 1 in another embodiment are illustrated in a schematic overview diagram. Each pipette tip extension 1 has a pipette tip 12 inserted into the inner cavity 7. In this embodiment, the pipette tip extension 1 includes at least three spacer elements 9 configured as extension rods and abutted against the inserted pipette tip 12 on their stop surfaces. Additionally, the pipette tip extension 1 in this embodiment includes a support rod 16 as a constriction element 13, which forms a sieve-like structure at its distal end 3 and, in this example, limits the insertion depth of the pipette tip 12, while allowing the formation of a gap. This gap between the distal end 30 of the pipette tip and the distal end 3 of the pipette tip extension 1 and the left side of the assembly of the pipette tip extension 1 and the pipette tip 12 is also highlighted here at a higher magnification. As can be seen, in this embodiment, the gap provides fluid connection between the inner cavity of the suction tip 12 and the fluid aspiration area 31 between the spacer element 9, the inner side 6 of the outer wall 4 and the outer side of the suction tip 12.

[0185] The right-side assembly—with Figure 7 The right assembly shown is similar—it is also sealed by the surface 19 of the microscope slide and the sample portion 21 positioned thereon. And similar to... Figure 7 Similarly, the suction tip extension 1 is filled with liquid 20 in its fluid suction area 31. Connections to corresponding components of the liquid handling workstation 25 can be similarly derived from... Figure 7 The description.

[0186] Figure 9 Microscopic images of formalin-fixed paraffin-embedded (FFPE) sections of mouse kidneys purchased from Amsbio, LLC (part number MP-901) are shown below at higher magnification, with an overview and the selected areas below. A scale bar is given for each image.

[0187] like Figure 5A The assembly shown is used for processing tissue sections. The slides containing tissue sections have been processed according to the following protocol: The glass slide is placed on a heated metal block, which is preheated to 65°C.

[0188] Using the liquid handling device (Cavro® Omni Flex), 50 μl of nucleic acid extraction solution (part number QE09050, Lucigen Corporation) was aspirated using a Tecan 200 μl standard disposable pipette tip (part number 30057814, Tecan Systems, Inc.).

[0189] Assemble the pipette tip and pipette tip extension. Lower the assembly onto the tissue section, thereby closing the dispensing orifice of the pipette tip extension, and perform the following liquid treatment: 1. Dispense 25 μl from the pipette tip into the fluid aspiration area of ​​the assembly, thereby moving the liquid on the tissue section.

[0190] 2. Place the liquid on the tissue section and hold it in the fluid aspiration area for 30 seconds.

[0191] 3. Dispense 20 μl from the pipette tip into the fluid aspiration area and wait 500 milliseconds.

[0192] 4. Aspirate 20 μl back into the pipette tip and wait 500 milliseconds.

[0193] 5. Repeat steps 3 and 4 five times.

[0194] 6. Repeat steps 2 to 5 four times.

[0195] After this process, the entire volume of liquid is aspirated back into the pipette tip.

[0196] The pipette tip in the tissue section rises from the assembly.

[0197] The liquid treatment was repeated on three additional areas of the tissue section.

[0198] The upper microscopic image provides an overview of the tissue section after liquid treatment as described above. The four treated areas are visible as black circles. The lower image shows the areas within the white circles at a higher magnification. In both images, a clear boundary is created between the untreated tissue areas (indicated as "FFPE tissue") and the treated areas (indicated as "dissolved areas"). From the higher magnification image, it can be inferred that the liquid treatment has caused changes on the surface. It can be inferred that the liquid treatment extracted the tissue or its components from paraffin embedding into the treatment liquid.

[0199] The remaining structures visible on the treated area—besides the glass of the microscope slide—may include paraffin residue, unremoved cell debris, and / or solids remaining after the evaporation of the extraction liquid.

[0200] Figure 9The results of an exemplary method performed using a possible embodiment of a pipette tip extension used in an assembly with a pipette tip are shown as an example. Other embodiments may be used depending on the desired application. The approach may be modified, for example, depending on the objectives of the analysis.

[0201] Figure 10 A schematic cross-sectional view of a pipette tip extension 1 is shown, which includes at least one spacer element 9 adapted to position a fixed pipette tip 12 within the extension 1. The fixed pipette tip 12 is shown here with a typical shape, wherein the extended, thin distal portion abutted by the spacer element 9 is shown side-cut on the right. Regardless of whether a disposable or fixed pipette tip is used, the pipette tip extension 1 is constructed to provide a stable and secure base. The insertion depth can also be controlled by the previously described constriction element 13 or, for example, by the force used to insert the pipette tip 12.

[0202] Figures 11A to 11D Schematic cross-sectional views of different variations of the pipette tip extension 1 are shown. The variations differ in their shape relative to the outer wall 4, the number, size, and construction of the spacer elements 9, and their effects on the size and position of the fluid aspiration area 31 and the pipette tip receiving area 32. The central axis 11 of the pipette tip extension 1 is indicated by a dashed line.

[0203] The pipette tip receiving area 32 is understood here as the area or space (having a substantially circular cross-section) within the inner cavity 7 of the pipette tip extension 1 that will be occupied by the pipette tip 12 when the pipette tip extension 1 is attached to the pipette tip 12, and the area where the pipette tip 12 abuts against the spacer element 9. The potential location for inserting the pipette tip 12, or its outer boundary, is shown as the circular boundary of the pipette tip receiving area 32.

[0204] The fluid aspiration area 31 is shown here as a shaded area, which should indicate that this area can be filled with liquid 20 when the suction tip 12 is inserted and the dispensing orifice 14 is closed, for example, by surface 19. As previously described and shown, the fluid aspiration area 31 or the cavity 7 of the suction tip extension 1 is not covered or closed at the proximal end of the suction tip extension 1. This allows for pressure compensation as liquid moves between the inserted suction tip 12 and the remaining cavity 7 or fluid aspiration area 31. Liquid can submerge the spacer element 9, for example, when disposed offset from the proximal end of the suction tip extension 1.

[0205] Figure 11AThe illustration shows a substantially concentric arrangement of the suction tip receiving area 32 within the inner cavity 7 of the suction tip extension 1. The suction tip extension 1 has a circular cross-section, and three spacer elements 9 are regularly distributed around the periphery of the inner side 6. Each spacer element 9 is constructed as a trapezoidal rod forming a protrusion of the outer wall 4, and each rod has substantially the same construction. The area that can receive liquid 20, i.e., the fluid aspiration area 31, is defined by the inner side 6 of the outer wall 4, the spacer elements 9, and the outer side of the suction tip 12 in the assembly.

[0206] Figure 11B The diagram illustrates the eccentric arrangement of the suction tip receiving area 32 within the cavity 7 of the suction tip extension 1. The suction tip extension 1 has a circular cross-section. Four spacer elements 9 are provided, regularly distributed around the periphery of the inner side 6 of the outer wall 4. Two spacer elements 9 are exemplary, having a similar trapezoidal shape, while the two remaining spacer elements 9 have a semi-circular shape that extends less into the cavity 6 compared to the trapezoidal elements. This asymmetrical configuration of the spacer elements 9 positions the suction tip 12 eccentrically relative to its own central axis, and the resulting fluid aspiration area 31 is also asymmetrically distributed within the cavity 7 of the suction tip extension 1.

[0207] Figure 11C The concentric arrangement of the suction tip receiving area 32 within the inner cavity 7 of the suction tip extension 1 is shown. The suction tip extension 1 has an elliptical cross-section. Four spacer elements 9 are provided, each constructed as a quadrilateral rod, regularly distributed around the periphery of the inner side 6 of the outer wall 4. The concentric position of the suction tips 12 is achieved by the construction of the spacer elements 9, wherein two of the rods extend further into the inner cavity 7 and protrude toward the central axis 11 than the other two rods, thereby balancing the varying distance from the outer wall 4 about the central axis 11. The depth of the spacer elements 9 is adjusted (see also...) Figure 13C The volume of the fluid absorption zone 31 can also be adjusted.

[0208] Figure 11D The concentric arrangement of the suction tip receiving area 32 within the inner cavity 7 of the suction tip extension 1 is shown. The suction tip extension 1 has a square cross-section. Four spacer elements 9 are provided, each constructed as a quadrilateral rod, regularly distributed on the four inner sides 6 of the outer wall 4. The concentric position of the suction tips 12 is achieved by the construction of the spacer elements 9, wherein all rods extend into the inner cavity 7 and protrude the same length toward the central axis 11.

[0209] Figures 12A to 12I Different shapes of the dispensing hole 14 formed through the outer wall 4 of the suction tube tip extension 1 are illustrated by cross-sectional views. The illustrated cross-section is a circular cross-section. Figure 12A ), elliptical cross section ( Figure 12B), with a double elliptical cross section ( Figure 12C ),square( Figure 12D ) or quadrilateral ( Figure 12E ) cross section, triangular cross section ( Figure 12F ), clover-shaped cross section ( Figure 12G ), has a notch ( Figure 12H A quadrilateral shape or an octagonal cross section with or without multiple notches (not shown). Figure 12I ).

[0210] These figures illustrate that the shape of the dispensing orifice 14 can be adapted to certain desired applications or sizes of the envisioned area of ​​interest, such as to specific sections of different tissues. The shape can also be adapted, for example, to meet other requirements, which may make a particular shape requirement at least advantageous. For example, if the pipette tip extension 1 is constructed to receive two pipette tips 12, a double elliptical shape may be desired, such as... Figure 14 As shown. Other cross sections, such as those with asymmetrical shapes, may be possible, but they are not explicitly shown here.

[0211] Figures 13A to 13C The diagram schematically shows views of the inner side 6 of the outer wall 4 of the suction tube tip extension 1 and of different embodiments of the spacer element 9.

[0212] Figure 13A A spacer element 9 is shown, which is constructed as an extension rod and is arranged flush with the proximal end of the outer wall 4 of the suction tip extension 1. The rod extends from the proximal end 2 toward the distal end 3 and has a width "a" corresponding to its circumference along the inner side 6 of the outer wall 4, a length "b" corresponding to its longitudinal dimension, and a depth "c" corresponding to its extension into the inner cavity 7 toward the central axis 11. The descriptions of depth a, length b, and width c are also generally applicable to the spacer element 9.

[0213] Figure 13BThe inner side 6 of the outer wall 4, comprising two spacer elements 9, is shown. The upper spacer element 9 is offset from the proximal end 2 and, as a width, is greater than the length b. Although this cross-sectional view cannot be used to assess, the upper spacer element 9 does not extend circumferentially but instead leaves at least a portion of the inner side of the outer wall 4 unoccupied, allowing fluid connection between the provided fluid aspiration area 31 and the surrounding atmosphere at the proximal end 2 of the suction tip extension 1. The lower spacer element 9 is constructed similarly to the upper spacer element 9, but also includes an additional protrusion at its distal end toward the central axis 11 of the suction tip extension 1. This additional protrusion serves as a structure that allows the distal end 30 of the suction tip 12 to be abutted and limits the insertion depth of the suction tip 12 within the suction tip extension 1. Thus, the additional protrusion acts as a constriction element 13 and facilitates the determination of the position of the suction tip 12 within the cavity 7 of the suction tip extension 1.

[0214] Figure 13C Different configurations of the spacer element 9 are schematically shown. All spacer elements 9 shown are arranged offset from the proximal end 2 of the outer peripheral wall 4. The spacer element 9 shown is configured with more or fewer extension rods or as a cylindrical protrusion. It is possible to combine spacer elements 9 configured in different ways to achieve a desired base for a specific suction tip 12 within the suction tip extension 1. For example, a large number of extension rods may be arranged along the same route from the proximal end 2 to the distal end 3. This distribution can be particularly advantageous for achieving a mixing effect between the liquid 20 and a portion of the dissolved material from the treated tissue. In addition to simple extension dimensions, offset forms (e.g., serpentine extensions) may also be possible.

[0215] Further distal, an additional constriction element 13 is shown for controlling the insertion depth of the suction tube tip 12. On the left, a spacer is shown, which includes additional protrusions at its distal end, as also... Figure 13B As shown in the middle. On the right, a single constriction element 13 is shown, which is a simple protrusion directly from the inner side 6 of the outer wall 6, and also provides a stop or stop surface that can be abutted against the distal end 30 of the suction tube tip 12.

[0216] The geometry corresponding to the inner gap of the fluid absorption zone 31 can be adjusted by correspondingly adjusting the geometry of the spacer(s)(s) used and the geometry of the outer wall 4. For example, it may be particularly desirable to minimize the fluid absorption zone 31 when only a small volume of liquid 20 should be used; in this case, special emphasis needs to be placed on the geometry of the spacer(s)(s) that minimizes the potential fluid trapping effect.

[0217] Figure 14A pipette tip extension 1, configured to receive two pipette tips 12, is shown schematically in high definition. In this exemplary embodiment, the pipette tip extension includes a height-thickened outer wall 4, providing two separate receiving holes 8 and two cavities 7, each cavity 7 including a separate pipette tip receiving area 32 occupied by the corresponding pipette tip 12. In each cavity, the corresponding pipette tip 12 is separated from the inner side 6 of the outer wall 4 by a spacer element 9. For each cavity 7, one of the spacer elements 9 is seen and shown cut in cross-sectional view.

[0218] The pipette tip extension 1 includes two additional seals 15 at its distal end 3. Each seal surrounds one of the dispensing orifices 14. In this configuration, simultaneous treatment of adjacent areas on the sample is allowed, as each of the two pipette tips 12 can be used to treat a separate area on the sample. Further increases in the pipette tip receiving area 32 may be possible, but are not shown here.

[0219] Figure 15 The steps of the demonstration method are illustrated schematically. The diagram shows a pipette tip 12 containing liquid 20 and a pipette tip extension 1 including a spacer element 9. To attach the pipette tip extension 1 to the pipette tip 12, the pipette tip 12 can be inserted into the pipette tip extension 1 through its receiving hole 8. For example, the pipette tip 12 can be mounted on the pipette of an automated liquid handling workstation and can automatically move into the pipette tip extension 1. The direction of this movement is indicated by arrows, and the corresponding liquid handling workstation 25 is not shown in this figure. Assembly of the pipette tip 12 and the pipette tip extension 1 can be performed by moving the pipette tip extension 1 to the distal end 30 of the pipette tip 12 or by moving the pipette tip 12 and the pipette tip extension 1 relative to each other. The assembly steps are indicated by boxed arrows.

[0220] For the pipette tip extension 1, two spacer elements 9 are shown, arranged at different heights. The upper spacer element 9 is arranged flush with the proximal end 2 of the pipette tip extension 1, and the lower spacer element 9 is arranged in the lower half of the pipette tip extension 1. The spacer elements 9 are shown as being cut. Although not visible here, the spacer elements 9 do not extend circumferentially and close the proximal end 2 in any case, but they are configured to leave the proximal end 2 of the pipette tip extension substantially open to the surrounding atmosphere.

[0221] The assembly, comprising a pipette tip extension 1, a pipette tip 12, and a spacer element 9, is then placed onto the sample. In this figure, the sample is a sample section 21 fixed on the upper surface 19 of a microscope slide. The pipette tip extension 1 shown includes a sealing portion 15 (a circumferential seal in this example) at its distal end 3, which ensures that the distal end 3 of the pipette tip extension 1 is sealed tightly through, for example, the surface of the sample and / or, for example, the surface of the carrier. The nature of the sealing portion 15 can be adapted to the nature of the sample to which the pipette tip extension 1 is used. For example, if the pipette tip extension 1 is to be used to process a deeply frozen tissue sample, different materials can be used, as if it were to be used to process cell cultures on a Piper plate or bacterial colonies on an agar plate. As a supplement or alternative, the sealing effect can be controlled using the force used to place and hold the assembly of the pipette tip extension 1, spacer element 9, and pipette tip 12 onto and onto the sample.

[0222] When the pipette tip extension 1 is placed on the sample using other components of the assembly, and the desired area of ​​interest is positioned within the dispensing orifice 14 of the pipette tip extension 1 and sealed by the sealing portion 15 and / or the distal end of the outer wall 4, liquid 20 is dispensed from the pipette tip 12 into the fluid aspiration zone 31, which is generated by the assembly. Thus, fluid flow is generated over the sample via the gap and the fluid aspiration zone 31, which is located within or below the dispensing orifice 14. Since the dispensing opening 14 is closed by the sample 21 and / or surface 19, it is important that the pipette tip extension 1 also remains open at its proximal end 2 when the pipette tip 12 is inserted into the pipette tip extension 1, as this ensures that pressure compensation is possible when liquid 20 is dispensed from the pipette tip 12 and fluid flow can be generated over the sample 21. This can be achieved, for example, by the construction of the spacer element 9, as previously described.

[0223] The repeated movement of the liquid 20 between the pipette tip 12 and the fluid aspiration area 31 of the pipette tip extension 1 (indicated by the curved double arrows) allows for the arbitrarily maintained fluid flow above the sample below the dispensing orifice 14 of the pipette tip extension. This repeated dispensing and aspiration of the liquid via the pipette tip 12, representing repeated movement of the liquid, is also referred to here as mixing, as this type of liquid movement is perfectly suited for effectively mixing different components. In this example, liquid mixing is not contemplated, but it is possible to achieve a mixing effect: by maintaining continuous flow above the sample surface, the sample is continuously subjected to the influence of the liquid 20. Thus, the components of the sample can be isolated from the sample and received by the liquid 20, as indicated by the slightly coarse shading of the liquid. The effect can be further enhanced if a liquid 20 that promotes the isolation of tissue components is used. By selecting the liquid 20 to be used, the desired effect of the liquid can be specifically directed to a particular area of ​​interest below / within the dispensing orifice 14.

[0224] Particularly suitable liquids 20 are, for example, liquids used for holding, culturing, and / or storing samples, such as buffers or cell culture solutions. Examples of buffers mentioned here are HEPES-(hydroxyethylpiperazine ethanesulfonic acid) buffer, sodium dihydrogen phosphate buffer, or TRIS-based (tris(hydroxymethylaminomethane)) buffer. Suitable cell culture solutions for human and / or animal cell culture may be, for example, Dalberg modified Eagle medium (DMEM) or other liquids for culturing eukaryotic cells or media for culturing microorganisms, such as lysogenic broth (LB medium) for culturing bacterial cells.

[0225] Other suitable liquids 20 are, for example, reagents for sample processing. Processing may be, for example, cell lysis reactions, staining reactions, binding reactions and / or removal / dissolution of embedding agents or portions thereof (deparaffinization steps of frozen and formalin-fixed paraffin-embedded tissue sections) or, for example, extraction reactions for extracting proteins or nucleic acids from corresponding electrophoresis gels.

[0226] As an alternative to or supplement to the liquid mixing-type movement, a soaking step is also possible (not shown here). In such a soaking step, the entire volume or only a portion of the liquid is dispensed from the pipette tip 12 onto the sample to completely cover or wet the sample below and / or within the dispensing orifice 14. The liquid 20 may remain there, for example, to facilitate incubation, and after a certain period of time, the liquid may be drawn back into the pipette tip 12 or moved into the fluid aspiration area 31, for example, for another subsequent mixing step.

[0227] After the liquid flow is applied to the area of ​​the sample below or within the dispensing orifice 14, the liquid can then be drawn back into the pipette tip 12 for use in subsequent method steps. Such subsequent steps can be, for example, transfer of liquid 20 to another container 20 or tube, as in... Figure 15 The middle section shows the final step. It is possible to retain the pipette tip extension 1 at the distal end 30 of the pipette tip 12, as also... Figure 15 As shown, the suction tip extension 1 is pre-removed, either manually or automatically via the ejection system of the liquid handling workstation 25.

[0228] As a supplement or alternative, depending on the desired treatment of the liquid and the components from the sample, the assembly may, for example, be placed on another area of ​​the same sample.

[0229] Figure 16 A flowchart illustrating an example of a method for processing a sample is provided. The method may include the following steps: - An isolation zone for the sample is created using a first fluid reservoir. The first fluid reservoir encloses the distal end of a second fluid reservoir. The isolation zone for the sample is sealed relative to the rest of the sample by the first fluid reservoir (e.g., by the distal end of the first fluid reservoir).

[0230] - Connect the isolation zone of the sample to the second fluid reservoir in a fluid manner.

[0231] - The fluid is distributed from the second fluid reservoir to the first fluid reservoir, thereby generating fluid flow on the sample in the isolation zone along the first direction.

[0232] - Fluid is drawn from the first fluid reservoir into the second fluid reservoir, thereby generating fluid flow on the sample in the isolation zone along the second direction.

[0233] The effect of the fluid (e.g., liquid) can be increased by applying bidirectional fluid flow. This is advantageous, for example, when components of a sample or the sample itself should be collected by a limited volume of liquid. For instance, when nucleic acids should be extracted from a tissue sample, it is often problematic that only small amounts of nucleic acids are available, and enhancement steps (e.g., precipitation steps) are typically required to obtain nucleic acids available at appropriate concentrations. In particular, by repeatedly applying bidirectional fluid flow, the amount of components collected by the liquid can be significantly increased without increasing, for example, the volume of liquid 20 to be used for component isolation.

[0234] Figure 17A flowchart illustrating other specified method steps for processing a sample is provided. The method described herein is specifically for processing a sample slice 21, which is, for example, fixed on a surface 19, such as a flat surface of a microscope slide. To allow the creation of an isolation zone for the sample by means of a first fluid reservoir fluidly connected to a second reservoir, a pipette tip 12, a pipette tip extension 1, and at least one spacer element 9 may also be provided.

[0235] The pipette tip 12, the pipette tip extension 1, and at least one spacer element 9 are assembled into a functional unit adapted to perform the method. Optionally, one or more constriction elements 13 may be provided. The configuration of each element of the assembly may be selected as previously described, and the different elements may be freely configured and combined into any combination as needed.

[0236] Liquid 20 is drawn in by a suction tip, preferably using an automated liquid handling workstation 25. Liquid 20 may be drawn in before different components are assembled; however, it is also possible to draw in liquid 20 when the assembly (not shown) has already been formed.

[0237] The assembly is moved to the sample, specifically to sample section 21 on a microscope slide as described herein. The assembly is then placed onto the desired region of interest on the sample section 21 and / or the microscope slide. A seal is established by the distal end 3 of the pipette tip extension 1, in this example, contacting the surface or penetrating the sample to a certain depth, thus isolating the region of interest, or a portion thereof, from the surrounding sample. Furthermore, the isolated region is then fluidly connected to the pipette tip 12, specifically to the lumen of the pipette tip 12. Liquid 20 is dispensed from the pipette tip 12, flowing through the isolated region of the sample into the pipette tip extension 1. The isolated region of the sample is thus exposed to the liquid 20, and the liquid 20 is collected after exposure in the pipette tip extension 1 for use in other steps.

[0238] Figure 18Flowcharts illustrating other specified, additional, and optional method steps are shown schematically. Optionally, for example, liquid 20 can be repeatedly moved between pipette tip 12 and pipette tip extension 1 via a so-called mixed movement 8 (repeated aspiration and dispensing step). The sample is thus repeatedly exposed to the same liquid, which allows for, for example, enhancement of the sample components within the liquid. An optional step is immersion, in which liquid 20 is exposed to the sample without moving liquid 20. After exposing the isolated sample area to the desired time and / or to fluid flow of liquid 20, the liquid is aspirated back into pipette tip 12. Returning the liquid to pipette tip 12 allows for the performance of other processing steps. For example, the same liquid can be used for another sample area or another sample and / or area of ​​interest by sealing the distal end 3 of pipette tip extension 1 to another area and repeating one or more of the above steps. Thus, liquid 20 can be enhanced by additional sample components.

[0239] However, the assembly still containing liquid 20 can be moved to laboratory container 22, such as a glass or tube, and liquid 20 is dispensed into that container. Alternatively, immediately after sample processing and before liquid 20 is aspirated into container 22, the pipette tip extension 1, spacer element 9, and pipette tip 12 can be removed from the pipette tip, or the pipette tip extension 1, spacer element 9, and pipette tip 12 can remain assembled until liquid 20 is dispensed into container 22.

[0240] Regarding how to pass Figures 15 to 18 As an example of the method described, the method steps may be performed in another sequence where appropriate and desired. Additional, optional steps may be possible. To perform the method steps, the pipette tip 12 is mounted on a pipette, such as a manual pipette or the pipette of the automated liquid handling workstation 25, as previously described.

[0241] List of reference numerals

[0242] 1. Suction tube tip extension

[0243] 1.1 First part of the pipette tip extension

[0244] 1.2 The second part of the pipette tip extension

[0245] 2. Proximal end of the pipette tip extension

[0246] 3. The distal end of the pipette tip extension

[0247] 4. Outer wall of the suction tube tip extension

[0248] 5. The outer side of the outer wall

[0249] 6. Inner side of the outer wall

[0250] 7. The inner cavity of the suction tube tip extension

[0251] 8. Receiving hole for the suction tube tip extension

[0252] 9. Spacer elements

[0253] 10. Stopping surface of the spacer element

[0254] 11. Central axis of the suction tube tip extension

[0255] 12. Pipe tip

[0256] 13. Condensation element

[0257] 14. Dispensing hole of the suction tube tip extension

[0258] 15 Sealing section

[0259] 16 Support rods

[0260] 17 Inserts

[0261] 18 vehicles

[0262] 19 Surface

[0263] 20 Liquid

[0264] 21 Sample Section

[0265] 22. Pipette

[0266] 23. Vehicle stoppers

[0267] 24. Vehicle receiving area

[0268] 25 Liquid handling workstations

[0269] 26. Controller of the liquid handling workstation

[0270] 27. Suction head of the liquid handling workstation

[0271] 28. The outer wall of the pipette tip

[0272] 29. Proximal end of the pipette tip

[0273] 30. Distal end of the pipette tip

[0274] 31 Fluid Absorption Zone

[0275] 32. Pipe tip receiving area

[0276] 33. Proximal orifice of the pipette tip

[0277] 34. Distal orifice of the suction tube tip

[0278] 35. Proximal section of the pipette tip

[0279] 36. Middle section of the pipette tip

[0280] 37. Distal section of the pipette tip

[0281] h Clearance height

[0282] The lateral extension of the inner cavity of the l1 suction tube tip extension

[0283] Lateral extension of L2 distribution hole

[0284] a. Width of the spacer element

[0285] b. Length of the spacer element

[0286] c. Depth of the spacer element

Claims

1. A method for extracting subcellular elements and molecules from tissue sections using a liquid, the method comprising the following steps: Provide the tissue section on a microscope slide; An isolation surface area of ​​the tissue slice is generated by means of a first fluid reservoir, the first fluid reservoir encapsulating the distal end of a second fluid reservoir, and the isolation surface area of ​​the tissue slice is sealed relative to the remaining surface area of ​​the tissue slice; The isolation surface area of ​​the tissue slice is fluidly connected to the second fluid reservoir; Distributing the full volume or a portion of the volume of the liquid from the second fluid reservoir to the first fluid reservoir, thereby generating fluid flow on the tissue slice along a first direction in the isolation surface area; The isolation surface area is immersed in the liquid for a certain period of time, whereby the liquid contacts the isolation surface area of ​​the tissue section without applying fluid flow during the immersion period; as well as The liquid is drawn from the first fluid reservoir into the second fluid reservoir, thereby generating fluid flow on the tissue slice in the second direction in the isolation surface area.

2. The method according to claim 1, characterized in that, After dispensing the liquid from the second fluid reservoir to the first fluid reservoir, the process further includes one or more of the following steps: The isolated surface area of ​​the tissue section is subjected to temperature treatment, thereby allowing the liquid to be at a temperature suitable for the tissue section.

3. The method according to claim 2, characterized in that, Exposing the isolated surface area of ​​the tissue section to temperature treatment includes a heating step and / or a cooling step using a heating device and / or a cooling device that is in operational contact with the tissue section.

4. The method according to claim 1, characterized in that, After the liquid is drawn from the first fluid reservoir into the second fluid reservoir, one or more of the following steps are included: A second isolation zone of a tissue slice is generated by means of a first fluid reservoir, the first fluid reservoir continuously encapsulating the distal end of a second fluid reservoir, and the second fluid reservoir further comprising the liquid, the tissue slice being the same tissue slice or another tissue slice, and the second isolation zone of the tissue slice being treated by the method of treating the isolation surface area as claimed in claim 1; and / or The first fluid reservoir is exchanged by a third fluid reservoir, and the third fluid reservoir is constructed differently from the first fluid reservoir in terms of the size of the area in which the remaining area of ​​the tissue section is isolated and sealed, and / or in terms of the volume of liquid that can be distributed from the second fluid reservoir to the first fluid reservoir or the third fluid reservoir, and the second isolation area of ​​the tissue section is treated by the method of treating the isolation surface area as claimed in claim 1. and / or Discard the first fluid reservoir from the second fluid reservoir; and / or The liquid is distributed from the second fluid reservoir to a fluid container for further processing.

5. The method according to claim 1, characterized in that, The dispensing of the liquid and / or the aspiration of the liquid are performed using the total volume of the liquid present in the second fluid reservoir and / or a portion of the volume of the liquid present in the second fluid reservoir.

6. The method according to claim 1, characterized in that, The tissue sections are selected from a combination of the following: organize; Tissue sections; Cell or cell culture, including bacterial cells, fungal cells, plant cells, animal cells and / or human cells; as well as One or more components of tissue, tissue section, cells and / or cell culture.

7. The method according to claim 6, characterized in that, The tissue is prepared for tissue analysis.

8. The method according to claim 6, characterized in that, The tissue slices are provided on the surface.

9. The method according to claim 8, characterized in that, The surface is the surface of a microscope slide.

10. The method according to claim 1, characterized in that, The liquid is selected from a combination of the following: Buffers or cell culture media used for culturing and / or maintaining and / or storing one or more tissue sections; A reagent used to process the tissue sections.

11. The method according to claim 10, characterized in that, The reagents are used to perform cell lysis reactions, staining reactions, binding reactions, or to remove embedding agents.

12. The method according to claim 1, characterized in that, The liquid is used to perform a cell lysis reaction and to collect one or more components from the tissue sections selected from a combination of the following: Nucleic acid; protein; Including components such as carbohydrates, fatty acids, vitamins and / or hormones or other cellular compounds; and / or The combination of the above items.

13. The method according to claim 12, characterized in that, The tissue sections are formalin-fixed, paraffin-embedded tissue sections from biopsies or excised tumors.

14. The method according to any one of the preceding claims, characterized in that, One or more steps in each method can be performed manually using a pipette or automatically using a liquid handling workstation.

15. The method according to claim 1, characterized in that, The first fluid reservoir is provided by a suction tip extension configured to attach to the distal end of a suction tip. The suction tip extension includes a proximal end, a distal end, and an outer wall extending between the proximal end and the distal end. The outer wall forms a receiving hole at the proximal end for inserting the suction tip and a dispensing hole at the distal end. The second fluid reservoir is provided by a suction tip for dispensing and / or drawing in liquid; The suction tube tip is attached to the suction tube tip by inserting the distal end of the suction tube tip into the suction tube tip extension through the receiving hole of the suction tube tip extension; and The fluid connection between the suction tip extension and the suction tip is formed by means of at least one spacer element that separates the suction tip from the suction tip extension.

16. The method according to claim 15, characterized in that, The suction tube tip, the suction tube tip extension, and the at least one spacer element form a functional assembly, which is formed by multiple parts or as a single workpiece.

17. The method according to claim 15, characterized in that, The at least one spacer element is sized to establish a fluid aspiration zone between the inner side of the outer wall of the pipette tip extension and the outer side of the outer wall of the pipette tip, the fluid aspiration zone extending from the dispensing orifice of the pipette tip extension to the receiving orifice of the pipette tip extension, and the fluid aspiration zone being fluidly connected to the surrounding atmosphere at the receiving orifice and to the inner cavity of the pipette tip adjacent to the distal orifice of the pipette tip.

18. The method according to claim 15, characterized in that, The at least one spacer element is provided by the following: The suction tube tip extension; and / or The suction tip; and / or Independent insert.

19. The method according to claim 15, characterized in that, The at least one spacer element is configured to provide a frictional engagement attachment between the suction tip extension and the distal end of the suction tip.

20. The method according to claim 15, characterized in that, The suction tip is selected from a combination of disposable suction tips and fixed suction tips.

21. The method according to claim 15, characterized in that, The suction tip, the suction tip extension, and the at least one spacer element form an assembly, the assembly including at least one constriction element for controlling the insertion depth of the suction tip within the suction tip extension, the constriction element defining a gap height between the distal end of the inserted suction tip and the distal end of the suction tip extension.

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