Pipette tip with two positive angle steps

Abstract

The present invention relates to a pipette tip having two positive angular steps. The pipette tip (10) comprises an end portion (14), a first portion (20), a second portion (22) and a third portion (24) aligned along a central axis (A) of the pipette tip (10). The end portion (14) comprises an orifice (16) for aspirating and dispensing a fluid. A first bend (44) is formed in an inner surface (40) of the pipette tip (10) between the first portion (20) and the second portion (22) such that an angle (al) between the inner surface (40b) of the first portion (20) and the central axis (A) is smaller than an angle (a2) between the inner surface (40c) of the second portion (22) and the central axis (A). A second bend (46) is formed in the inner surface (40) of the pipette tip (10) between the second portion (22) and the third portion (24) such that the angle (a2) between the inner surface (40c) of the second portion (22) and the central axis (A) is smaller than an angle (a3) between the inner surface (40d) of the third portion (24) and the central axis (A).

Description

Technical Field

[0001] This invention relates to a pipette tip, for example, for use in laboratory automation equipment. Background Technology

[0002] Laboratory automation equipment is used to automate tasks performed by laboratory assistants, such as testing for specific diseases in patients. Typically, samples of blood, urine, stool, etc., from patients are collected and analyzed through biochemical procedures. These procedures include various operations such as adding substances, culturing, separating, and quantitative or qualitative measurements of the amount or presence of substances indicating a specific disease.

[0003] Samples are typically aspirated and dispensed using disposable pipette tips, which can be inserted into the nozzle of a handheld pipette or the nozzle of a movable head on automated laboratory equipment. Handheld pipettes can be mechanically driven by the operator or electrically driven. The geometry of the pipette tip is crucial for accurate aspiration and dispensing. Sometimes, it is desirable to be able to control the volume of sample liquid aspirated and dispensed as precisely as possible, especially when aspirating and dispensing small volumes.

[0004] Several types of pipette tips have been designed to meet different needs in the aspiration and dispensing process.

[0005] EP 3 272 851 B1 shows a pipette tip having a first cylindrical portion with an orifice, a conical portion, and a second cylindrical portion with a diameter greater than that of the first cylindrical portion.

[0006] US 2019 0344 258 A1 discloses a pipette tip having a conical portion with an orifice and a cylindrical portion.

[0007] EP 2 606 977 B1 shows several pipette tips, which are composed of cylindrical and conical portions.

[0008] EP 3 492 926 B1 shows a pipette tip consisting of conical sections with different opening angles. Summary of the Invention

[0009] The purpose of this invention is to provide a pipette tip that allows for the precise aspiration and dispensing of small amounts of liquid. Another purpose of this invention is to improve the accuracy and precision of liquid volumes aspirated or dispensed using automated laboratory equipment.

[0010] This objective is achieved through the subject matter of the present invention. Further exemplary embodiments will become apparent from the following description.

[0011] This invention relates to pipette tips. In summary, a pipette tip can be an elongated body with an internal chamber from which liquid or other fluid can be drawn or dispensed by changing the pressure. Typically, a pipette tip consists of several sections with different inner diameters, which can be cylindrical or conical.

[0012] Pipette tips can be designed for use with laboratory automation equipment, for example, they can have an attachment portion that will be inserted into the laboratory automation equipment. However, pipette tips can also be part of handheld devices.

[0013] According to embodiments of the invention, a pipette tip includes an end portion, a first portion, a second portion, and a third portion aligned along the central axis of the pipette tip, wherein the end portion includes an orifice for aspirating and dispensing fluids (particularly liquids, emulsions, or suspensions). The pipette tip may be substantially rotationally symmetrical with respect to the central axis. In particular, the end portion, the first portion, the second portion, and the third portion, as well as the cylindrical portion mentioned below, may be rotationally symmetrical.

[0014] According to an embodiment of the present invention, a first bend is formed in the inner surface of the pipette tip, between the first portion and the second portion, such that the angle between the inner surface of the first portion and the central axis is smaller than the angle between the inner surface of the second portion and the central axis. Furthermore, a second bend is formed in the inner surface of the pipette tip, between the second portion and the third portion, such that the angle between the inner surface of the second portion and the central axis is smaller than the angle between the inner surface of the third portion and the central axis.

[0015] Between bends, the inner surface of the pipette tip may be continuous and / or may have little or no curvature. Bends are also characterized by areas of relatively high curvature and / or small radius of curvature on the inner surface. The curvature of the inner surface at the bend is much greater than the curvature of the inner surface between bends (e.g., at least 10 times higher).

[0016] Each of the first and second bends, as well as the bends mentioned below, may be around the central axis and / or may have a circular shape centered on the central axis.

[0017] The angle of a surface relative to its central axis can be defined as the angle between a line inside the surface and the central axis, where the line is a cross-section of the surface having a plane passing through the central axis.

[0018] In other words, the angles of the inner surfaces of the first, second, and third sections increase in this order, where these inner surfaces can be rotationally symmetrical about the central axis. In this way, two bends are formed, which can be considered as positive bends, i.e., they bulge inwards towards the inside of the pipette tip. When the fluid level passes through one of these bends during aspiration or dispensing, the boundary of the fluid surface remains or adheres to that bend due to capillary forces, even when the pressure inside the tip changes. There can be a range of volumes that can be aspirated or dispensed, all of which have fluid levels at the corresponding bends. This effect can be used to better control the amount of fluid within the pipette tip. In particular, at the bends, since the boundary of the fluid surface does not move and is not subject to uncontrollable movement caused by capillary forces, the amount of fluid aspirated and dispensed can be controlled quite precisely using pressure changes.

[0019] The corresponding effect can occur at negative bends (i.e., bends protruding away from the inside of the pipette tip). There, the fluid level may rise and fall without pressure changes, resulting in an uncontrollable volume range. Depending on the liquid and tip material, a combination of positive and negative bends can be advantageous.

[0020] The pipette tip described herein has a positive bend only at the ends comprising the first, second, and third sections. Therefore, control over the volume of aspirated and dispensed is improved at a lower volume.

[0021] According to an embodiment of the invention, the angle between the inner surfaces of the first portion and the second portion (i.e., the angle at the first bend) is greater than 1° and / or less than 5°. Additionally and / or optionally, the angle between the inner surfaces of the second portion and the third portion (i.e., the angle at the second bend) is greater than 1° and / or less than 5°. Experiments and tests show that the angle at the bend should be greater than 1°. Otherwise, the aforementioned effect of fluid surface retention or adhesion becomes too weak. Furthermore, for angles greater than 5°, this effect generally becomes too strong and undesirable.

[0022] It is important to note that the actual angle size can deviate from the angle size provided here by up to 10%, meaning that the 1° angle mentioned above could be a true measured angle ranging from 0.9° to 1.1°. The same applies to the angles mentioned below.

[0023] According to embodiments of the invention, the angle between the inner surface of the first portion and the central axis is greater than 2° and / or less than 5°, particularly 3°. The angle between the inner surface of the second portion and the central axis may be greater than 3° and / or less than 9°, particularly 5°. The angle between the inner surface of the third portion and the central axis may be greater than 4° and / or less than 13°, particularly 6.5°.

[0024] Further testing showed that these absolute angles (compared to the relative angles between the parts) resulted in good controllable volume within the first, second, and third sections of the pipette tip.

[0025] According to an embodiment of the invention, the position of the first bend between the first and second portions is selected such that the internal volume of the pipette tip between the orifice and the first bend is between 0.3 μl (microliters) and 0.6 μl, particularly 0.5 μl. The first aspiration volume can be fixed at 0.5 μl. As another example, the first aspiration volume can be approximately 1.0 μl.

[0026] The position of the second bend between the second and third sections is chosen such that the internal volume of the pipette tip between the orifice and the second bend is between 0.8 μl and 1.2 μl, particularly 1.0 μl. The second aspiration volume can be fixed at 1.0 μl. The second aspiration volume can be 2 μl or even 5 μl. A range between 4.5 μl and 5.5 μl can also be chosen.

[0027] As described above, the volume of fluid in the pipette can be controlled very precisely at the bend. When the bend is positioned at a location where the pipette has a specific internal volume, the aspiration and dispensing of a certain amount of fluid with said specific internal volume can be controlled even more precisely.

[0028] According to an embodiment of the invention, the length of the third portion along the central axis is selected such that the internal volume of the pipette tip between the orifice and this length is at least the nominal volume of the pipette tip, such that it is at least 5 μl or at least 10 μl. The third portion can be used to aspirate much higher volumes of fluid than the first and second portions. The length of the third portion can also be selected such that the internal volume of the pipette tip between the orifice and this length is at least 5 times the internal volume of the pipette tip between the orifice and the second bend.

[0029] A cylindrical portion may also exist following the third section, and the nominal volume of the pipette is defined as the internal volume including the cylindrical portion. Where a defined volume is required, the third section may be omitted, and the second section and / or the cylindrical portion following the second section may be designed to allow for a larger volume.

[0030] As already mentioned, the inner surface of a pipette tip may have little or no curvature between bends. Such a surface can be defined by a truncated cone or a cylinder.

[0031] According to an embodiment of the invention, the inner surface of the first portion is conical, the inner surface of the second portion is conical, and / or the inner surface of the third portion is conical. In this document, "conical" refers to a truncated cone in a mathematical sense.

[0032] The end portion of the pipette tip may have a conical inner surface, and the inner surface between the end portion of the pipette tip and the first portion may have another bend.

[0033] According to an embodiment of the invention, another bend is formed on the inner surface of the pipette tip, between the end portion and the first portion.

[0034] According to an embodiment of the present invention, the angle between the inner surface of the end portion and the inner surface of the first portion is greater than 2° and / or less than 5°.

[0035] According to an embodiment of the invention, the inner surface of the end portion is cylindrical. The inner surface of the end portion may have the same radius as the orifice, which may be defined by the boundary of the inner surface.

[0036] It is important to note that, due to manufacturing processes, the inner surface of a cylindrical shape can have an angle of up to 0.5° relative to the central axis. For example, if a pipette tip is manufactured by injection molding, the inner surface may need to deviate slightly from a mathematically perfect cylinder so that the mold tool can be removed from the pipette tip after molding.

[0037] According to an embodiment of the invention, the common outer surface of the first, second, and third portions, and optionally the end portion, is conical. The angle of the outer surface relative to the central axis can be the angle of the third portion relative to the central axis. Therefore, the wall thickness of the pipette tip can be increased in the end portion, the first portion, and the second portion.

[0038] According to an embodiment of the present invention, a pipette tip includes an attachment portion for attaching the pipette tip to a nozzle of a laboratory automation device to change the pressure inside the pipette tip. The nozzle may be part of a moving head of the laboratory automation device. The attachment portion is aligned along the central axis of the pipette tip after a third portion and optionally a cylindrical portion (see below). The inner diameter of the attachment portion may be larger than the inner diameter of the third portion and / or the cylindrical portion. The angle between the inner surface of the attachment portion and the central axis may be smaller than the angle between the inner surface of the third portion and the central axis.

[0039] The attachment may also have longitudinal ribs on the outside of the pipette tip to reinforce the wall of the pipette tip there.

[0040] According to an embodiment of the invention, the attachment portion is formed such that another pipette tip of the same shape can be partially inserted into the attachment portion to reach at least a third portion for stacking the other pipette tip and the pipette tip.

[0041] According to an embodiment of the present invention, a pipette tip includes a cylindrical portion located between an attachment portion and a third portion, the cylindrical portion being aligned along the central axis of the pipette tip and positioned after the third portion. The cylindrical portion may have a length greater than the length of the pipette tip between the orifice and the beginning portion of the cylindrical portion. It is even possible that the length of the cylindrical portion is at least two or at least five times the length of the pipette tip between the orifice and the beginning portion of the cylindrical portion.

[0042] When the first and second bends (and another bend between the end portion and the first portion) are considered positive bends with increasing angles, a negative bend is formed between the third portion and the cylindrical portion, where the angle decreases as the distance from the orifice increases.

[0043] According to an embodiment of the present invention, a pipette tip includes a filter portion, which may be part of an attachment portion. The filter portion is aligned along the central axis of the pipette tip and may be located after the third portion and / or the cylindrical portion. The inner surface of the filter portion may include ribs extending radially around the central axis. The inner diameter of the filter portion may be larger than the inner diameter of the third portion and / or the cylindrical portion.

[0044] It is important to note that pipette tips may include more than three parts and / or more than two optimized volumes. A single optimized volume is also possible.

[0045] These and other aspects of the invention will become apparent from the embodiments described below and will be set forth with reference to the embodiments described below. Attached Figure Description

[0046] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0047] Figure 1 A cross-sectional view of a pipette tip according to an embodiment of the present invention is shown.

[0048] Figure 2 It shows Figure 1 An enlarged view of one end of a pipette tip.

[0049] Figure 3 Two bases stacked on top of each other are shown. Figure 1A cross-sectional view of a pipette tip.

[0050] Figure 4 A cross-sectional view of a pipette tip according to another embodiment of the present invention is shown.

[0051] The reference numerals used in the accompanying drawings and their meanings are listed in summary form in the reference numeral list. In principle, the same parts have the same reference numerals in the accompanying drawings. Detailed Implementation

[0052] Figure 1 A pipette tip 10 is shown, which can be used with manual pipettes or laboratory automation equipment. The pipette tip 10 includes a body 12 that is substantially rotationally symmetrical about a central axis A.

[0053] The pipette tip 10 can be divided into several parts with different geometric shapes.

[0054] The end portion 14 includes an orifice 16 for drawing fluid into the inner cavity 18 of the pipette tip 10. The orifice 16 may be circular with a diameter between 0.3 mm and 1.0 mm, and / or the outer end of the pipette tip 10 may have a diameter of approximately 0.8 mm. The end portion 14 may have a length of approximately 0.5 mm.

[0055] Along axis A, the first portion 20, the second portion 22, and the third portion 24 follow sequentially after the end portion 14. All these portions, as well as the end portion, are rotationally symmetric about the central axis A and / or have a circular cross-section perpendicular to the central axis A. Furthermore, a slightly elliptical cross-section is also possible. The length of the first portion 20 is approximately 2.0 mm, the length of the second portion 22 is approximately 1.2 mm, and the length of the third portion is approximately 12.4 mm. Here and below, the length depends on the desired volume of the respective portion, which in turn depends on the diameter of the respective portion.

[0056] End portion 14, first portion 20, second portion 22, and third portion 24 are rotationally symmetric about axis A. Similarly, a slightly elliptical cross-section is possible.

[0057] The pipette tip 10 also includes an attachment portion 26 having an opening 28 opposite to the orifice 16. The attachment portion 26 is designed for connection to a nozzle of a laboratory automation device or a handheld pipette, which can be inserted into the opening 28. At its outer end, the attachment portion 26 includes a rib 30 extending substantially parallel to the central axis A and positioned on the outer side of the pipette tip 10 and its body 12. Figure 1The image shows a cross-section through a pair of opposing ribs 30. Apart from the ribs 30, the thickness of the wall 32 of the attachment portion 26 is similar to the thickness in the region of the wall 32 where the ribs 30 are no longer present (i.e., the region facing the orifice 16).

[0058] The attachment portion 26 has a length of approximately 19 mm. Apart from the ribs, the attachment portion 26 is rotationally symmetric about axis A.

[0059] The attachment portion 26 connects to the third portion 24. At one end connected to the third portion 24, the attachment portion 26 includes a filter portion 34. The filter portion 34 is designed to receive a cylindrical filter element and / or has internal ribs 36 surrounding a central axis A on the inside of the pipette tip 10. The length of the filter portion 34 is approximately 4 mm. The filter portion 34 is rotationally symmetrical about axis A.

[0060] The pipette tip 10 and its body 12 can be made of a plastic material. The plastic material can be conductive (e.g., with graphite additives) or non-conductive (e.g., polypropylene). The pipette tip 10 can be manufactured by injection molding, wherein the outer surface 38 is formed by an outer mold tool and the inner surface 40 is formed by an inner mold tool.

[0061] The inner surface 40a of the end portion 14 is cylindrical and has the same diameter as the orifice 16. The inner surfaces 40b of the first portion 20, 40c of the second portion 22, and 40d of the third portion 24 are conical. The terms "cylindrical" and "conical" refer to the shell surfaces of the corresponding shapes. Pipette tips without cylindrical end portions may also exist. Such tips may have very short end portions, which may be the lower end of the first portion providing the orifice.

[0062] It is possible that the opening shape of the end of the inner surface 40d of the third part (which enters into the inner surface of the attachment part 26) is like a trumpet, that is, having a continuously increasing surface angle relative to the central axis A.

[0063] The inner diameters of the first section 20, the second section 22, and the third section 24 increase continuously with increasing distance from the orifice 16. Within a section, the angle relative to the central axis A can be constant. As the distance to the end section increases, the angle increases from one section to another.

[0064] Figure 2Enlarged views of portions 14, 20, 22, and 24 of the pipette tip 10 are shown. It can be seen that a bend 42 is formed between the inner surface 40a of the end portion 14 and the inner surface 40b of the first portion 20, a bend 44 is formed between the inner surface 40b of the first portion 20 and the inner surface 40c of the second portion 22, and a bend 46 is formed between the inner surface 40c of the second portion 22 and the inner surface 40d of the third portion 24.

[0065] As described above, when the pipette tip is filled to the corresponding bends 44 and 46, the accuracy and precision of the fluid volume to be aspirated and dispensed can be improved. The positions of bends 44 and 46 can be selected to improve accuracy at a given volume.

[0066] exist Figure 1 and Figure 2 In the illustrated embodiment, the position of the bend 44 is selected such that the internal volume of the pipette tip 10 between the orifice 16 and the bend 44 is approximately 0.5 μl. Similarly, the position of the second bend 46 is selected such that the internal volume of the pipette tip 10 between the orifice 16 and the second bend 46 is approximately 1.0 μl.

[0067] The third part 24 may be much longer than the first part 20 and the second part 22, and / or may have a much larger internal volume. The length of the third part 24 along the central axis A is selected such that the internal volume of the pipette tip 10 between the orifice 16 and this length is at least the nominal volume of the pipette tip 10, such that it is, for example, greater than 5 μl, for example, 10 μl.

[0068] Bends 42, 44, and 46 are formed by abrupt changes in the angle between the inner surface 40 of the pipette tip and the axis A. Each of the angles α1, α2, and α3 existing between the central axis A and surfaces 40b, 40c, and 40d is greater than the previous angle; that is, the inner surface 40 of the pipette tip 10 opens at each bend 42, 44, and 46. In the case of the cylindrical end portion 14, only bend 42 may exist.

[0069] The angle α1 between the inner surface 40b of the first part 20 and the central axis A is smaller than the angle α2 between the inner surface 40c of the second part 22 and the central axis A. The angle α2 between the inner surface 40c of the second part 22 and the central axis A is smaller than the angle α3 between the inner surface 40d of the third part 24 and the central axis A.

[0070] As described above, the following angle range has been shown to achieve the beneficial effects of increasing the controllability of absorption and dispensing, as well as the accuracy of the volume defined by bends 44 and 46.

[0071] The angle α1 between the inner surface 40b of the first part 20 and the central axis A can be greater than 2° and / or less than 5°, for example, 3°. The angle α2 between the inner surface 40c of the second part 22 and the central axis A can be greater than 3° and / or less than 9°, for example, 5°. The angle α3 between the inner surface 40d of the third part 24 and the central axis A can be greater than 4° and / or less than 13°, for example, 6.5°.

[0072] The angle β1 between the inner surface 40b of the first part 20 and the inner surface 40c of the second part 22 is the difference between angles α2 and α1. Angle β1 is greater than 1° and / or less than 5°. The angle β2 between the inner surface 40c of the second part 22 and the inner surface 40d of the third part 24 is the difference between angles α3 and α2. Angle β2 is greater than 1° and / or less than 5°.

[0073] The outer surface 38 of the pipette tip 10 does not necessarily have a bend. In this embodiment, the common outer surface 38a of the end portion 14, the first portion 20, the second portion 22, and the third portion 24 is conical.

[0074] Figure 3 It shows Figure 1 and Figure 2 The diagram shows a pipette tip 10 and another pipette tip 10' of the same design. An attachment portion 26 is shown formed such that the other pipette tip 10' can be partially inserted into the attachment portion 26 to reach at least a third portion for stacking the other pipette tip 10' and the pipette tip 10. The pipette tips 10, 10' are suspended in a tray 48 having a hole 50. The diameter of the hole 50 is smaller than the outer diameter of the rib 30, and the diameter of the hole 50 is larger than the outer diameter of the connecting portion without the rib 30. The tray 48 is maintained at a distance by spacers 52 to optimally utilize the stacking space.

[0075] The outer diameter of the third portion 24, which has the largest outer diameter among portions 14, 20, 22, and 24, is smaller than the inner diameter of the attachment portion 26 at the opening 28. Furthermore, the length of the attachment portion 26 (without the optional filter portion 34) is at least 80% of the total length of portions 14, 20, 22, and 24.

[0076] Figure 4 A pipette tip 10 is shown, which also includes a cylindrical portion 54 located between the third portion 24 and the attachment portion 26. The nominal volume of the pipette 10 can be significantly increased by utilizing the cylindrical portion 54. The length of the cylindrical portion 54 is greater than the length of the pipette tip 10 between the orifice 16 and the cylindrical portion 54, i.e., longer than portions 14, 20, 22, and 24.

[0077] Figure 4The other parts of the pipette tip 10 can be designed as Figures 1 to 3 The corresponding part of the pipette tip 10. In particular, Figure 4 The pipette tip 10 also includes bends 44 and 46, which, as described above, increase the accuracy of aspiration and dispensing.

[0078] Figure 4 The pipette tip 10 includes a bend 56 between the inner surface 40d of the third portion 24 and the inner surface 40e of the cylindrical portion 54; however, the bend 56 protrudes away from the central axis A, unlike the bends 42, 44, 46.

[0079] Although the invention has been detailed and described in the accompanying drawings and the foregoing description, such description and description are to be considered illustrative or exemplary, not restrictive; the invention is not limited to the disclosed embodiments. Other variations of the disclosed embodiments can be understood and implemented by those skilled in the art and those practicing the claimed invention through study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. The fact that certain measures are recited in mutually different dependent claims does not mean that combinations of these measures cannot be used advantageously. Any reference numerals in the claims should not be construed as limiting the scope.

[0080] List of reference numerals

[0081] A central axis

[0082] 10 pipette tips

[0083] 12 main bodies

[0084] 14 End portion

[0085] 16-hole opening

[0086] 18 inner cavity

[0087] 20 Part 1

[0088] 22 Part Two

[0089] 24 Part Three

[0090] 26 Attachment

[0091] 28 openings

[0092] 30 external ribs

[0093] 32 walls

[0094] 34 Filter Section

[0095] 36 internal ribs

[0096] 38 outer surface

[0097] 38a outer surface

[0098] 40 inner surface

[0099] Inner surface of 40a 14

[0100] 40b 20 inner surface

[0101] 40c 22 inner surface

[0102] 40d 24 inner surface

[0103] 42. The bend between 40a and 40b

[0104] 44. The bend between 40b and 40c

[0105] The bend between 46, 40c, and 40d

[0106] The angle between α1A and 40b

[0107] The angle between α2A and 40c

[0108] The angle between α3A and 40d

[0109] The angle between β1 40b and 40c

[0110] The angle between β2 40c and 40d

[0111] 48 pallets

[0112] 50 holes

[0113] 52 spacers

[0114] 54 cylindrical parts

[0115] Inner surface of 40e 54

[0116] 56 bends

Claims

1. A pipette tip (10), comprising: The end portion (14), the first portion (20), the second portion (22) and the third portion (24) are aligned along the central axis (A) of the pipette tip (10); The end portion (14) includes an orifice (16) for drawing in and dispensing fluid; The first bend (44) is formed in the inner surface (40) of the pipette tip (10) between the first part (20) and the second part (22), such that the angle (α1) between the inner surface (40b) of the first part (20) and the central axis (A) is smaller than the angle (α2) between the inner surface (40c) of the second part (22) and the central axis (A). The second bend (46) is formed in the inner surface (40) of the pipette tip (10) between the second part (22) and the third part (24), such that the angle (α2) between the inner surface (40c) of the second part (22) and the central axis (A) is smaller than the angle (α3) between the inner surface (40d) of the third part (24) and the central axis (A). The first bend (44) and the second bend (46) are formed such that when the fluid level passes through one of the first bend (44) and the second bend (46) during fluid suction or dispensing, the boundary of the fluid surface remains or adheres to the first bend (44) and the second bend (46) due to capillary forces, even when the pressure inside the suction head changes; Wherein, the angle (β1) between the inner surface (40b) of the first part (20) and the inner surface (40c) of the second part (22) is greater than 1° and / or less than 5°; Wherein, the angle (β2) between the inner surface (40c) of the second part (22) and the inner surface (40d) of the third part (24) is greater than 1° and / or less than 5°; The position of the first bend (44) is selected such that the internal volume of the pipette tip (10) between the orifice (16) and the first bend (44) is between 0.3 μl and 0.6 μl.

2. The pipette tip (10) according to claim 1. in, The angle (α1) between the inner surface (40b) of the first part (20) and the central axis (A) is greater than 2° and / or less than 5°; Wherein, the angle (α2) between the inner surface (40c) of the second part (22) and the central axis (A) is greater than 3° and / or less than 9°; The angle (α3) between the inner surface (40d) of the third part (24) and the central axis (A) is greater than 4° and / or less than 13°.

3. The pipette tip (10) according to claim 1. in, The position of the second bend (46) is selected such that the internal volume of the pipette tip (10) between the orifice (16) and the second bend (46) is between 0.8 μl and 1.2 μl.

4. The pipette tip (10) according to claim 1. in, The length of the third portion (24) along the central axis (A) is selected such that the internal volume of the pipette tip (10) between the orifice (16) and the length is at least the nominal volume of the pipette tip (10), such that it is at least 5 μl.

5. The pipette tip (10) according to claim 1. in, The inner surface (40b) of the first part (20) is conical; The inner surface (40c) of the second part (22) is conical; The inner surface (40d) of the third part (24) is conical.

6. The pipette tip (10) according to claim 1. in, Another bend (42) is formed in the inner surface (40) of the pipette tip (10), between the end portion (14) and the first portion (20).

7. The pipette tip (10) according to claim 1. in, The angle (α1) between the inner surface (40a) of the end portion (14) and the inner surface (40b) of the first portion (20) is greater than 2° and / or less than 5°.

8. The pipette tip (10) according to claim 1. in, The inner surface (40a) of the end portion (14) is cylindrical.

9. The pipette tip (10) according to claim 1. in, The common outer surface (38a) of the first part (20), the second part (22) and the third part (24) is conical.

10. The pipette tip (10) according to claim 1. in, The pipette tip (10) includes an attachment portion (26) for attaching the pipette tip (10) to the nozzle of a laboratory automation device to change the pressure inside the pipette tip (10); The attachment portion (26) is aligned along the central axis (A) of the pipette tip (10) after the third portion (24).

11. The pipette tip (10) according to claim 10. in, The attachment portion (26) is configured such that another pipette tip (10') can be partially inserted into the attachment portion (26) to reach at least the third portion for stacking the other pipette tip (10') and the pipette tip (10).

12. The pipette tip (10) according to claim 1. in, The pipette tip (10) includes a cylindrical portion (54) which is aligned along the central axis (A) of the pipette tip (10) after the third portion (24); The length of the cylindrical portion (54) is greater than the length of the pipette tip (10) between the orifice (16) and the cylindrical portion (54).

13. The pipette tip (10) according to claim 1. in, The pipette tip (10) includes a filter portion (34) aligned along the central axis (A) of the pipette tip (10) and following the third portion (24); The inner surface (40) of the filter portion (34) includes ribs (36) that extend radially around the central axis (A).

Images