Pipetting tip, tip arrangement, liquid handling system and method for illuminating a biological sample

Abstract

A pipetting tip (5) comprising at least one sidewall (7), a distal end (8) and a proximal end (10), wherein the pipetting tip (5) is configured to serve as a lightguide, wherein illumination light (9) being emitted from a light source (6) is coupled into the pipetting tip (5) and is transmitted inside the at least one sidewall (7), preferably via internal reflection, and wherein the illumination light (9) exits the pipetting tip (5) at the distal end (8). Further, a tip arrangement (2), a liquid handling system (1) and a method for illuminating a biological sample (16) are described.

Description

[0001] Pipetting tip, tip arrangement, liquid handling system and method for illuminating a biological sample

[0002] The present invention relates to a pipetting tip comprising at least one sidewall, a distal end and a proximal end.

[0003] Further, the present invention relates to a tip arrangement comprising a pipetting tip and a light source.

[0004] Furthermore, the present invention relates to a liquid handling system comprising a tip arrangement, a vessel and an imaging system.

[0005] Moreover, the present invention relates to a method for illuminating a biological sample.

[0006] Pipetting of a biological sample, for example a cell or a biological entity, being immersed in a liquid medium, is an indispensable step in biology and related disciplines, allowing precise handling and manipulation of the biological sample to obtain experimental results and study biological processes. Pipetting is crucial in various experimental procedures like cell culture, molecular biology techniques (PCR, sequencing), immunology assays, and drug discovery.

[0007] Accurate pipetting ensures precise measurement and transfer of biological samples, vital for maintaining consistency and reproducibility in experiments. Further, proper pipetting techniques minimize the risk of contamination, ensuring the purity of samples and experimental results. A further advantage of pipetting is that it allows researchers to handle biological samples gently, minimizing shear forces and maintaining cell viability.

[0008] For pipetting cells or other biological entities, the pipetting tip is immersed into the liquid medium containing the same. Then, the liquid together with the biological sample is drawn up into the pipetting tip. Further, the liquid together with the biological sample is transferred to the desired location, such as a microplate, tube, or another vessel.

[0009] Several challenges and issues can arise when pipetting biological samples, potentially impacting experimental results. One of these problems is the correct localization of the biological sample. In the state of the art, either the pipette or the light source must be placed at an angle to illuminate the biological sample leading to pipetting constraints or optical aberrations.

[0010] Document WO 2016 / 156051 A1 discloses a pipette comprising a body portion for aspirating a fluid sample into a pipetting tip. The body portion comprises a light source and a detector, the pipette body provides an optical path of light that passes from the light source to the sample and an optical path for light from the sample to the detector. This design is complex and therefore expensive to manufacture. Furthermore, the illumination of the sample to be pipetted is not sufficient.

[0011] One of the objectives of the present invention is therefore to provide a pipetting tip, a tip arrangement and a liquid handling system that allow easy and secure pipetting with a simple construction. Further, an improved method for illuminating a biological sample is to be provided.

[0012] In an embodiment, the present invention may solve the objective by a pipetting tip comprising at least one sidewall, a distal end and a proximal end, wherein the pipetting tip is configured to serve as a lightguide, wherein illumination light being emitted from a light source is coupled into the pipetting tip and is transmitted inside the at least one sidewall, preferably via internal reflection, and wherein the illumination light exits the pipetting tip at the distal end.

[0013] In an embodiment, the present invention may solve the objective by a tip arrangement comprising a pipetting tip according to any one of claims 1 to 5 and a light source, wherein illumination light being emitted from the light source is coupled into the pipetting tip and is transmitted inside the at least one sidewall, and wherein the illumination light exits the pipetting tip at the distal end. In an embodiment, the present invention may solve the objective by a liquid handling system comprising a tip arrangement according to any one of claims 6 to 10, a vessel and an imaging system.

[0014] In an embodiment, the present invention may solve the objective by a method for illuminating a biological sample, preferably by using a liquid handling system according to any one of claims 11 to 14, wherein illumination light being emitted from a light source is coupled into the pipetting tip and wherein the illumination light exiting the distal end of the pipetting tip is directed onto the biological sample.

[0015] One of the advantages may be that the pipetting tip itself, especially its sidewalls, serves as a lightguide for illuminating the biological sample. Rays of illumination light may be hitting the pipetting tip in many different angles and may be strayed within the pipetting tip partially. A part of this injected illumination light may be travelling in internal reflection inside the at least one sidewall towards the distal end and may serve as illumination for the biological sample below the distal end of the pipetting tip. Hence, direct illuminating and localizing the sample is achieved with a simple construction as a separate lightguide is not necessary. A further advantage may be that since the distal tip is emitting the light, the point of interest, i.e., the area in front of the distal tip, is always illuminated. Therefore, the biological sample may be illuminated before, during and after the aspiration by the pipetting tip placed, preferably vertically, above the sample. This at least reduces optical aberrations and pipetting constraints. Furthermore, one of the advantages may be that light is emitted from the distal end of the pipetting tip, regardless of whether the pipetting tip is filled or not.

[0016] Further features, advantages and preferred embodiments are disclosed or may become apparent in the following.

[0017] The term “pipetting tip” refers in particular in the claims, preferably in the description to all types of pipetting tips. The pipetting tip may comprise an elongated hollow body with a distal end and a proximal end, wherein a channel extends from the proximal end to the distal end that comprises an intake opening and wherein the channel is surrounded by at least one sidewall, depending on the cross section of the pipetting tip. The pipetting tip may comprise a circular cross section or a flat cross section or any arbitrary cross section. Alternatively or additionally, the pipetting tip may be straight or tapered and / or may comprise a straight or tapered channel. The volume of the pipetting tip may be in the range of 0,05 pl ml to 5 ml, preferably 0,09 pl ml to 3 ml, more preferably 0,1 pl ml to 2 ml .

[0018] According to a preferred embodiment of the invention, said pipetting tip comprises a thermoplastic, preferably a polycarbonate (PC), polystyrene (PS), cyclic olefin polymer (COP), cyclic olefin copolymer (COC) and / or acrylic. This may have the advantage that the pipetting tip is suitable for using it under laboratory conditions and is also a good light guide.

[0019] According to a preferred embodiment of the invention, said pipetting tip may be integral with a pipetting device and / or may be configured to be detachably connected to a pipetting device.

[0020] According to a preferred embodiment of the invention, said pipetting tip is transparent at least for light comprising the wavelength of the illumination light. This may enhance the pipetting tip to be used more effectively as a light guide.

[0021] According to a preferred embodiment of the invention, said pipetting tip is at least partly coated with a light reflecting material. This may prevent light from leaving the coated part of the pipetting tip while travelling to the distal end of the pipetting tip which may lead to more light being emitted from the distal end of the pipetting tip.

[0022] According to a preferred embodiment of the invention, said pipetting tip comprises less than two steps, preferably one step, or is step free between a coupling point of the light into the pipetting tip, for example a sidewall and / or a proximal end of the pipetting tip, and the distal end. This may prevent light from being scattered within the material of the pipetting tip so that the pipetting tip can be more efficiently used as a lightguide. The term “step free” is to be understood in the claims, preferably in the description, in its broadest sense and includes a pipetting tip comprising no steps within the pipetting tip, i.e. , a continuous pipetting tip.

[0023] According to a preferred embodiment of the invention, said illumination light is coupled into the at least one sidewall of the pipetting tip and / or the illumination light is coupled into a proximal end of the pipetting tip. Coupling the illumination light into the at least one sidewall of the pipetting tip may have the advantage that there is more space for positioning the light source in relation to the pipetting tip. Coupling the illumination light into the proximal end of the pipetting tip may enhance the intensity of the light being emitted from the distal end.

[0024] According to a preferred embodiment of the invention, said light source comprises a light emitting diode and / or a laser diode, preferably emitting light with a wavelength in the range of 380 nm to 750 nm. An advantage of a light emitting diode may be that the illumination light can be generated with low energy consumption. A laser diode might enhance the intensity of the illumination light.

[0025] According to a preferred embodiment of the invention, said light source is covered with a housing, a light shade and / or a lens for reducing stray light. This may have the advantage of minimizing losses, for example due to scattering, of the illumination light.

[0026] According to a preferred embodiment of the invention, said light source is arranged at a holder. This design may have the advantage that the pipetting tip and the light source can easily be positioned exactly relative to each other in order to achieve optimum coupling of the illumination light into the at least one sidewall of the pipetting tip. Further, the holder may be used for holding cabling and a light emitting diode or a laser diode. Furthermore, the pipetting tip may be arranged at a tip holder that is coupled with the holder of the light source.

[0027] According to a preferred embodiment of the invention, said imaging system is configured to receive and process illumination light that is reflected and / or scattered by and / or has transmitted the biological sample and / or the liquid. Alternatively or additionally, the imaging system could receive and evaluate fluorescent light that is emitted from the biological sample. In this case it might be advantageous to arrange an optical filter between the vessel and the imaging system. Furthermore, the imaging system may comprise a sensor, for example a light sensor, and / or a camera.

[0028] According to a preferred embodiment of the invention, said imaging system and the tip arrangement are positioned at opposite sides of the vessel and / or wherein the imaging system and the tip arrangement are positioned at a same side of the vessel. Arranging the imaging system and the tip arrangement at opposite sides of the vessel may have the advantage that a high resolution can be achieved. Positioning the imaging system and the tip arrangement at a same side of the vessel may provide a high contrast image of the biological sample.

[0029] According to a preferred embodiment of the invention, a surface of a liquid being filled into the vessel defines a vessel plane and wherein a longitudinal axis of the pipetting tip intersects the vessel plane at an angle in the range of 80° to 100°, preferably in the range of 85° to 95°, more preferably in the range of 88° to 92°, for example 90°. This may have the advantage that aberrations or pipetting constraints are prevented because the pipetting tip is at least essentially arranged vertically above the biological sample.

[0030] According to a preferred embodiment of the invention, said vessel is configured to receive a liquid, for example a culture medium, and a biological sample, preferably single cells, a monolayer of cells or multicellular biological entities, for example selected from the group consisting of: cell aggregates; organoids; spheroids; zebrafish eggs; zebrafish larvae; C. e / egans; tissue sections; biopsy tissue; and assembloids, or combinations thereof.

[0031] There are several ways how to design and further develop the teaching of the present invention in an advantageous way. To this end, it is to be referred to the patent claims subordinate to patent claims 1 , 6 and 11 on the one hand and to the following explanation of preferred examples of embodiments of the invention, illustrated by the drawing on the other hand. In connection with the explanation of the preferred embodiments of the invention by the aid of the drawing, generally preferred embodiments and further developments of the teaching will be explained.

[0032] In the drawing

[0033] Fig. 1 shows a liquid handling system according to an embodiment of the invention in a side view;

[0034] Fig. 2 shows a liquid tip arrangement according to an embodiment of the invention in a side view;

[0035] Fig. 3 shows a theoretical representation of an image captured by a liquid handling system according to an embodiment of the invention; and

[0036] Fig. 4 shows steps of a method according to an embodiment of the invention.

[0037] Figure 1 shows in a side view a liquid handling system 1 according to an embodiment of the invention. The liquid handling system 1 comprises a tip arrangement 2 according to an embodiment of the invention, a vessel 3 and an imaging system 4. The tip arrangement 2 comprises a pipetting tip 5 according to an embodiment of the invention and a light source 6.

[0038] The pipetting tip 5 comprises a sidewall 7 that is configured to serve as a lightguide. Figure 1 shows that the illumination light 9 being emitted by the light source is coupled into the pipetting tip 5 and exits the pipetting tip 5 at the distal end 8. In this embodiment, the illumination light 9 is coupled into the sidewall 7 of the pipetting tip 5. However, the illumination light 9 may additionally or alternatively coupled into the proximal end 10 of the pipetting tip. Further, the pipetting tip 1 is step free between the coupling point 11 of the illumination light 9 into the sidewall 7 of the pipetting tip 5. Since the tip arrangement 2 and the imaging system 4 are arranged at opposite sides of the vessel 3, the vessel 3 should comprise a material that is at least essentially transparent for the illumination light 9. Further, figure 1 shows that the light source 6 is covered with a housing 23 to reduce stray light. Furthermore, a light shade and / or a lens may be arranged for reducing stray light.

[0039] Moreover, the surface 12 of the liquid 13 that is filled into the vessel 3 defines a vessel plane 14. Figure 1 shows that the longitudinal axis 15 of the pipetting tip 5 intersects the vessel plane 14 at an angle of 90°. However, this angle may also be in the range of 80° to 100°, preferably in the range of 85° to 95°, more preferably in the range of 88° to 92°. Thus, the pipetting tip 5 allows direct illumination of the biological sample 16, for example single cells, a monolayer of cells or multicellular biological entities.

[0040] Figure 2 shows in a side view a tip arrangement 2 according to a further embodiment of the invention. The tip arrangement 2 comprises a pipetting tip 5 according to an embodiment of the invention and a light source 6. The pipetting tip 5 comprises a sidewall 7 that is configured to serve as a lightguide. Further, the illumination light 9 being emitted by the light source 6 is coupled into the pipetting tip 5 and exits the pipetting tip 5 at the distal end 8. In this embodiment, the illumination light 9 is coupled into the sidewall 7 of the pipetting tip 5. However, the illumination light 9 may additionally or alternatively be coupled into the proximal end 10 of the pipetting tip. Further, the pipetting tip 1 is step free between the coupling point 11 of the illumination light 9 into the sidewall 7 of the pipetting tip 5, i.e. , the pipetting tip 5 is straight in this region.

[0041] The pipetting tip 5 is arranged at a tip holder 24 and the light source 6 are arranged at a holder 17. The tip holder 24 and the holder 17 of the light source 6 are coupled to each other. Further, a light shade 18 is attached for blocking light that is emitted from the light source 6 but is not directed to the pipetting tip 5. In this embodiment the light source 6 comprises a light emitting diode 6 that is attached to a printed circuit board 19, preferably a glass-reinforced epoxy laminate material printed circuit board, preferably a "FR-4" category material as defined in the NEMA LI 1-1998 standard. Figure 3 shows a theoretical representation of an image 20 captured by a liquid handling system 2 according to an embodiment of the invention, whereas the imaging system 4 and the tip arrangement 2 are positioned at opposite sides of the vessel 3.

[0042] The image 20 depicts a ring of light 21 being emitted by the distal end 8 of the pipetting tip 5. Further, the biological sample 16, for example a single cell or a multicellular entity, is shown as a dark spot 22 in the middle of the ring of light 21. Moreover, the liquid 13 can be seen between the dark spot 22 and the ring of light 21 as well as outside the ring of light 21 . Figure 3 therefore shows that by using a liquid handling system 2 according to the invention, the biological sample 16 and the ring of light 21 created by the pipetting tip are clearly visible.

[0043] Figure 4 shows steps of a method according to an embodiment of the present invention.

[0044] The method comprises the steps of:

[0045] - coupling S1 illumination light being emitted from a light source into the pipetting tip,

[0046] - directing S2 the illumination light exiting the distal end of the pipetting tip onto the biological sample.

[0047] Many modifications and other embodiments of the invention set forth herein will come to mind to the one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

C l a i m s1. Pipetting tip (5) comprising at least one sidewall (7), a distal end (8) and a proximal end (10), wherein the pipetting tip (5) is configured to serve as a lightguide, wherein illumination light (9) being emitted from a light source (6) is coupled into the pipetting tip (5) and is transmitted inside the at least one sidewall (7), preferably via internal reflection, and wherein the illumination light (9) exits the pipetting tip (5) at the distal end (8).

2. Pipetting tip (5) according to claim 1 , characterized in that the pipetting tip (5) comprises a thermoplastic, preferably a polycarbonate (PC), polysterene (PS), cyclic olefin polymer (COP), cyclic olefin copolymer (COC) and / or acrylic, and / or glass and / or any other transparent material.

3. Pipetting tip (5) according to claim 1 or 2, characterized in that the pipetting tip (5) is transparent at least for light comprising the wavelength of the illumination light (9).

4. Pipetting tip (5) according to any one of claims 1 to 3, characterized in that the pipetting tip (5) is at least partly coated with a light reflecting material.

5. Pipetting tip (5) according to any one of claims 1 to 4, characterized in that the pipetting tip (5) comprises less than two steps, preferably one step, or is step free between a coupling point (11 ) of the light into the pipetting tip (5) and the distal end (8).

6. Tip arrangement (2) comprising a pipetting tip (5) according to any one of claims 1 to 5 and a light source (6), wherein illumination light (9) being emitted from the light source (6) is coupled into the pipetting tip (5) and is transmitted inside the at least one sidewall (7), and wherein the illumination light (9) exits the pipetting tip (5) at the distal end (8).

7. Tip arrangement (2) according to any one of claims 1 to 6, characterized in that the illumination light (9) is coupled into the at least one sidewall (7) of the pipetting tip (5), and / or that the illumination light (9) is coupled into a proximal end (10) of the pipetting tip (5).

8. Tip arrangement (2) according to any one of claims 1 to 7, characterized in that the light source (6) comprises a light emitting diode and / or a laser diode, preferably emitting light with a wavelength in the range of 380 nm to 750 nm.

9. Tip arrangement (2) according to any one of claims 1 to 8, characterized in that the light source (6) is covered with a housing (23), a light shade (18) and / or a lens for reducing stray light.

10. Tip arrangement (2) according to any one of claims 1 to 9. characterized in that the light source (6) is arranged at a holder (17).

11. Liquid handling system (1) comprising a tip arrangement (2) according to any one of claims 6 to 10, a vessel (3) and an imaging system (4).

12. Liquid handling system (1) according to claim 11 , characterized in that the imaging system (4) and the tip arrangement are positioned at opposite sides of the vessel (3) and / or wherein the imaging system (4) and the tip arrangement are positioned at a same side of the vessel (3).

13. Liquid handling system (1 ) according to claim 11 or 12, characterized in that a surface (13) of a liquid (13) being filled into the vessel (3) defines a vessel plane (14) and wherein a longitudinal axis (15) of the pipetting tip (5) intersects the vessel plane (14) at an angle in the range of 80° to 100°, preferably in the range of 85° to 95°, more preferably in the range of 88° to 92°, for example 90°.

14. Liquid handling system (1 ) according to any one of claims 11 to 13, characterized in that the vessel (3) is configured to receive a liquid (13), for example a culture medium, and a biological sample (16), preferably single cells, amonolayer of cells or multicellular biological entities, for example selected from the group consisting of: cell aggregates; organoids; spheroids; zebrafish eggs; zebrafish larvae; C. e / egans; tissue sections; biopsy tissue; and assembloids, or combinations thereof.

15. Method for illuminating a biological sample (16), preferably by using a liquid handling system (1) according to any one of claims 11 to 14, wherein illumination light (9) being emitted from a light source (6) is coupled into the pipetting tip (5) and wherein the illumination light (9) exiting the distal end (8) of the pipetting tip is directed onto the biological sample (16).

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