Improved washing system for a probe

Abstract

Systems for washing a probe, such as a pipette of an autosampler. The systems comprise a magnetically active component disposed within a probe cleaning well. Application of a magnetic field to the magnetically active component draws cleaning fluid into the well. The accumulating cleaning fluid spills over an edge of the well and is drained away, while fresh cleaning fluid is drawn into the well.

Description

IMPROVED WASHING SYSTEM FOR A PROBEFIELD

[0001] The present disclosure relates to washing systems used to remove sample from a probe used in automated laboratory systems. The disclosure is applicable at least to equipment of the type used in high throughput analytical laboratories, and also equipment used in small scale research applications to handle samples for analysis.BACKGROUND

[0002] Automation has revolutionized the operation of analytical and research laboratories. By integrating advanced robotics, instrumentation, and software, laboratory automation optimizes workflows, enhances process reproducibility, as well as reducing labor costs

[0003] At its core, laboratory automation aims to streamline experimental workflows by replacing manual tasks with automated processes. This involves the integration of robotic systems capable of performing a wide array of tasks, ranging from sample preparation and handling, sample analysis, output data analysis and storage.

[0004] Laboratory automation encompasses a diverse array of methodologies tailored to specific process requirements. Liquid handling robots, equipped with precision pipetting systems, enable accurate dispensing of reagents and samples, facilitating high-throughput screening and assay development. Integrated robotic workstations automate sample preparation workflows, including DNA extraction, purification, and amplification, revolutionizing genomics and molecular biology research. High-content imaging systems coupled with automated analysis software enable rapid acquisition and analysis of large-scale image datasets, empowering researchers in drug discovery and cell biology.

[0005] Automation is especially prevalent in high throughput analytical laboratories of the type used to analyze samples of clinical, environmental and industrial origin. Such laboratories aretasked with performing analysis on hundreds or thousands of individual samples per day, and automation is absolutely essential to operations.

[0006] Many process steps in an automated workflow require the transport of a liquid sample for analysis from one location to another. Typically a probe is lowered into a sample container, and an aliquot of the same is aspirated into the probe. The probe may be in the form of a syringe, or a hollow needle with a sample holding loop, for example. The probe is then moved to a destination, such as an analytical instrument into which the sample aliquot is ejected for analysis. An autosampler is one type of apparatus that is commonly used in laboratory automation to perform liquid sample transfer as just described.

[0007] As will be appreciated, where a probe is required to contact multiple different samples it is necessary to wash away any sample remaining on the probe after ejection. Such washing is typically achieved with an automatic wash station. After sample ejection, the probe is lowered into a cleaning well of the wash station. An external pump is used to draw cleaning liquid from a reservoir, and to continuously flush the cleaning well with the liquid thereby removing sample from the probe. The continuous flushing causes the cleaning well to overflow into an adjacent effluent well. Liquid in the effluent well is removed therefrom by any appropriate means.

[0008] Wash stations comprise a number of parts, any of which can fail and require replacement or repair. Even short pauses in the operation of an automated laboratory system can dramatically impact workflows leading to backing up of samples awaiting analysis.

[0009] It is an aspect of the present disclosure to provide an improvement in prior art wash stations. It is a further aspect of the present disclosure to provide a useful alternative to prior art wash stations.

[0010] The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present disclosure. It is notsuggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The foregoing aspects and other features of the disclosed embodiment are explained in the following description, taken in connection with the accompanying drawings, wherein:

[0012] FIG. 1A is a diagrammatic illustration in lateral view of an exemplary probe washing system as implemented in a laboratory wash station in accordance with aspects of the present disclosure. This embodiment comprises an impeller at the base of a cleaning well, driven by stators disposed under a support surface.

[0013] FIG. IB is a diagrammatic illustration in lateral view of the impeller of the probe washing system drawn in FIG. 1.

[0014] FIG. 2 is a diagrammatic illustration in lateral view of an exemplary probe washing system as implemented in a laboratory wash station in accordance with aspects of the present disclosure. This embodiment is devoid of an effluent well. Instead, effluent runs down a vertical face of the cleaning well and into a shallow tray connected to a drain.

[0015] FIG. 3 A is a diagrammatic illustration in lateral view of an exemplary probe washing system as implemented in a laboratory wash station in accordance with aspects of the present disclosure. This embodiment comprises a centrifugal pump that is driven by stators mounted on an outside wall of the cleaning well.

[0016] FIG. 3B is a diagrammatic illustration in lateral perspective view of a centrifugal pump useful in the probe washing system drawn in FIG. 3A.

[0017] FIG. 4A is a diagrammatic illustration in lateral view of an exemplary probe washing system as implemented in a laboratory wash station in accordance with aspects of the present disclosure. This embodiment comprises an axial flow pump that is driven by stators mounted within an underlying structure.

[0018] 4B is a diagrammatic illustration in lateral perspective view of an axial flow pump useful in the probe washing system drawn in FIG. 4A.

[0019] FIG. 5 is a diagrammatic illustration in lateral view of an exemplary probe washing system as implemented in a laboratory wash station in accordance with aspects of the present disclosure. This embodiment is the same as that drawn in FIG. 1, although with the stators mounted within the cleaning well.

[0020] Unless otherwise indicated herein, features of the drawings labelled with the same numeral are taken to be the same features, or at least functionally similar features, when used across different drawings.

[0021] The drawings are not prepared to any particular scale or dimension and are not presented as being a completely accurate presentation of the various embodiments.SUMMARY

[0022] In a first aspect, but not necessarily the broadest aspect, there is provided a probe washing system for use in a wash station of an automated laboratory system, the system comprising: a probe cleaning well configured to receive a probe, and comprising an inlet to admit a probe cleaning liquid; a magnetically active liquid mover disposed within the probe cleaning well, the liquid mover configured to draw a probe cleaning liquid through the inlet and into the probe cleaning well; anda magnetically active driver configured to magnetically couple with the liquid mover and to cause movement thereof, wherein movement of the liquid mover draws the probe cleaning liquid through the inlet and into the probe cleaning well so as to be contactable to a probe received therein.

[0023] In one embodiment of the first aspect, the magnetically active driver comprises an electromagnetic field generator configured to receive electrical power and generate a magnetic field thereabout, the magnetic field configured to move the liquid mover.

[0024] In one embodiment of the first aspect, the electromagnetic field generator is isolated from the interior of the probe cleaning well.

[0025] In one embodiment of the first aspect, the electromagnetic field generator is disposed inside the probe cleaning well and has a coating or a housing to effect the isolation.

[0026] In one embodiment of the first aspect, the electromagnetic field generator is disposed outside the probe cleaning well.

[0027] In one embodiment of the first aspect, the electromagnetic field generator is disposed beneath a surface supporting the probe cleaning well.

[0028] In one embodiment of the first aspect, the electromagnetic field generator functions as a stator, and the liquid mover functions as a rotor.

[0029] In one embodiment of the first aspect, the liquid mover comprises a plurality of blades configured to move the liquid.

[0030] In one embodiment of the first aspect, the liquid mover is configured for rotary or nonrotary motion.

[0031] In one embodiment of the first aspect, the liquid mover is an impeller.

[0032] In one embodiment of the first aspect, the liquid mover comprises one or magnets, and the one of more magnets are isolated from the interior of the probe cleaning well.

[0033] In one embodiment of the first aspect, the isolation is provided by a coating on, or a housing about, the liquid mover.

[0034] In one embodiment of the first aspect, the liquid mover is disposed in a lower region of the probe cleaning well.

[0035] In one embodiment of the first aspect, the probe cleaning well has a vertical axis, and the liquid mover draws the liquid at an angle to, or generally orthogonal to, the vertical axis, and directs the liquid generally upwardly along the vertical axis.

[0036] In one embodiment of the first aspect, the system of claim 1, comprising an effluent collector configured to receive cleaning fluid that has contacted a probe received in probe cleaning well.

[0037] In one embodiment of the first aspect, the system is configured such that actuation of the liquid mover causes overflow of cleaning liquid from the probe cleaning well.

[0038] In one embodiment of the first aspect, the system is configured such that probe cleaning liquid overflowing from the probe cleaning well enters an effluent collector.

[0039] In one embodiment of the first aspect, the effluent collector is continuously or periodically drained so as to be capable of receiving overflow from the probe cleaning well.

[0040] In one embodiment of the first aspect, the system is configured to be alternately mountable on, and demountable from, a support surface.

[0041] In a second aspect, there is provided a wash station comprising the system of any embodiment of the first aspect.

[0042] In a third aspect, there is provided an automated laboratory system comprising the wash station of any embodiment of the second aspect.

[0043] In a fourth aspect, there is provided a method of washing a probe, the method comprising actuating the magnetically active driver of the probe washing system of any embodiment of the first aspect so as to draw a probe cleaning liquid into the probe cleaning well, wherein the probe cleaning liquid contacts a probe disposed within the probe cleaning well.DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS

[0044] After considering this description it will be apparent to one skilled in the art how the disclosure is implemented in various alternative embodiments and alternative applications. However, although various embodiments of the present disclosure will be described herein, it is understood that these embodiments are presented by way of example only, and not limitation. As such, this description of various alternative embodiments should not be construed to limit the scope or breadth of the present disclosure. Furthermore, statements of advantages or other aspects apply to specific exemplary embodiments, and not necessarily to all embodiments, or indeed any embodiment covered by the claims.

[0045] Throughout the description and the claims of this specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps.

[0046] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may.

[0047] As used herein, positional terms such as “lateral”, “across”, “above”, “below”, “higher”, “lower”, “upward”, “downward”, “plan view” and the like are to be considered with reference to a washing station as used in a normal upright position.

[0048] It will be appreciated that not all embodiments of the disclosure described herein have all of the advantages disclosed herein. Some embodiments may have a single advantage, while other may have no advantage at all and are merely a useful alternative to the prior art.

[0049] In one aspect, there is provided a probe washing system for use in a wash station of an automated laboratory system, the system comprising: a probe cleaning well configured to receive a probe, and comprising an inlet to admit a probe cleaning liquid; a magnetically active liquid mover disposed within the probe cleaning well, the liquid mover configured to draw a probe cleaning liquid through the inlet and into the probe cleaning well; and a magnetically active driver configured to magnetically couple with the liquid mover and to cause movement thereof,wherein movement of the liquid mover draws the probe cleaning liquid through the inlet and into the probe cleaning well so as to be contactable to a probe received therein.

[0050] The present system is an advance over prior art systems that rely on a conventional electric motor driven pump placed inline between a reservoir of a probe cleaning liquid and an inlet of the washing cell. The present does not rely on any such pump, and instead comprises a magnetically active liquid mover, such as an impeller or other means, disposed within the probe cleaning well to draw probe cleaning liquid from a reservoir and into the well. The magnetically active liquid mover is caused to move, and therefore draw probe cleaning liquid by an electromagnetic field generated nearby. Typically, two or more stator coils are mounted adjacent to the magnetically active liquid mover, with alternate powering thereof causing the required movement. The alternate powering is typically timed by a microcontroller so as to achieve a desired oscillation or revolution frequency, and also the period of power-on and power-off for each stator.

[0051] The use of a magnetically driven probe cleaning liquid mover provides advantages in reliability, thereby substantially lessening downtime of a wash station. Conventional pumps comprise many moving parts each of which contributes to frictional wear and the possibility of ear up to the point of failure. The electric motor is one part prone to failure, but other parts such as spindle and bearing also presenting points. Conventional pumps also require seals, typically about the electric motor spindle which drives the pump action, and also to sealing housing portions. Seals will inevitable perish over time leading to leaks.

[0052] The use of a magnetic drive requires only one moving part (the liquid mover), the electromagnetic field to drive the movement being provided by solid state means. Moreover, no special seals are required given that the electromagnetic field can act across a wall of the probe cleaning well thereby allowing for the liquid mover to be completely enclosed within the probe cleaning well.

[0053] To further describe the present disclosure, reference is made to the following non-limiting embodiments.

[0054] FIG. 1A and FIG. IB show an embodiment of the present disclosure comprising a probe cleaning system (10) as part of a wash station. The system (10) comprises a probe cleaning well (15) being generally elongate and vertically oriented so as to be capable of receiving a probe (20) lowered downwardly thereinto. It will be appreciated that the probe (20) is not a component of the system (10), but is a component of another apparatus in an automated laboratory system. The probe (20) may be, for example, a component of an autosampler and in that context requires cleaning after contact with a sample for analysis.

[0055] The probe cleaning well (15) comprises an inlet (25) for receiving a probe cleaning liquid. Typically, the source of the liquid is a reservoir (not dawn) being a part of the wash station for which the present system is also a part. To assist movement of probe cleaning liquid into the probe cleaning well (15), the reservoir may be disposed higher than the inlet (25).

[0056] An impeller (30) is disposed adjacent the inlet (25). The impeller comprises a central axis (35), and a spindle (40) extending downwardly therealong providing for rotary motion about the central axis (35). The spindle (40) inserts into and is supported by the floor (45) of the probe cleaning well (15).

[0057] The impeller (30) comprises 4 blades (3 of which are visible and marked 50). A bar magnet (not visible, but presented in ghosted form and marked 52) is contained within and extends across two diametrically opposed blades (50) such that the magnet’s north pole is disposed in one blade, and its south pole disposed in the other.

[0058] Disposed beneath an underlying surface (47) are paired stator coils (55) connected to a power supply (not shown). The function of the stator coils (55) is to generate electromagneticfields configured to magnetically couple the magnet (52) of the impeller (30). By alternating power between the two stator coils (55), the magnet (32) is caused to rotate, thereby rotating the impeller (30) about is central axis (40).

[0059] The underlying surface (47) may be an upper surface of the wash station of which the present system is a part.

[0060] Rotation of the impeller (30) causes bulk flow of liquid upwardly through the probe cleaning well (15), as indicated by the dashed arrows. A negative pressure is therefore generated in the liquid about the inlet (25) thereby drawing liquid from a reservoir and into the probe cleaning well (15). The upwardly bulk liquid flow causes an overflow of liquid into an adjacent effluent well (60). The effluent well (60) remains capable of continuously accepting liquid overflow by way of the gravity draining function provided by outlet (65). The continuous movement of probe cleaning liquid upwardly through the probe cleaning well (15) functions to remove contaminant from the probe (20). The one-way flow of liquid to the effluent well (60) prevents backflow and re-contamination of the probe (40).

[0061] Various considerations may apply in the design of the present system to optimize operation.

[0062] The impeller is subject to the hydrostatic pressure of the liquid column immediately above it, that pressure contracting to some extent the function of the impeller (30) in moving liquid upwardly. The blades (x) of the impeller (30) may be dimensioned, shaped, angled, or otherwise configured to overcome the hydrostatic pressure to ensure that liquid continuous to move upwardly and overflow from the probe cleaning well (15).

[0063] In addition or alternatively, the probe cleaning well (15) may be dimensioned so as to minimize the volume of liquid above the impeller, thereby minimizing hydrostatic pressure. While the probe cleaning well (15) must be of a minimum height (such as 1, 2, 3, 4 or 5 cm) so as toensure a length of the probe (40) contacts probe cleaning liquid, reduction in width and / or depth of the probe cleaning well (15) may be effected.

[0064] Hydrostatic pressure may be overcome by rotating the impeller (30) at a sufficiently high RPM so as increase the velocity of the liquid exiting therefrom.

[0065] Another possibility is to dispose a shroud around the impeller to force liquid outwardly through a restricted aperture so as to increase the pressure of liquid exiting.

[0066] It will be appreciated that liquid will always be required about the impeller. In the absence of liquid, the impeller (30) is incapable of generating the negative liquid pressure adjacent the inlet (25) and accordingly fresh probe cleaning liquid will not be drawn into the cleaning well (15). A solution to that problem may be to ensure that the liquid reservoir drains from its floor, and the floor is maintained at a height above the upper bounding volume of the impeller (30) thereby ensuring that when the impeller (30) ceases rotation it remains covered in liquid. This approach has the added advantage of preventing or limiting backflow of liquid from the cleaning well (which may be contaminated with sample washed from the probe (40) into the reservoir and associated supply line.

[0067] A further problem may be the uncontrolled entry of liquid from the reservoir when the impeller stops, and hydrostatic pressure from liquid in the reservoir forces liquid into the cleaning well (15). That may be addressed by ensuring that the reservoir is not placed so high that liquid is able to overflow out of the cleaning well.

[0068] The need to keep liquid about the impeller and prevent backflow can be addressed by a stopcock valve being associated with the inlet (25). The valve is normally closed, but opens under the negative pressure conditions provided when the impeller commences rotation thereby allow for liquid to be drawn from the reservoir into the cleaning well (15). At the end of a washcycle, the impeller (30) stops and the hydrostatic pressure of the liquid column in the cleaning well (15) causes liquid to attempt to flow back toward the reservoir. The initial backflow causes the stopcock to shut, thereby preventing backflow and retaining liquid in the cleaning well (15).

[0069] Further exemplary embodiments are provided in the drawings described below.

[0070] FIG. 2 shows an embodiment that is devoid of the effluent well of the embodiment of FIG. 1 A. Effluent overflowing from the probe cleaning well runs down a vertical face and into a shallow tray connected to a drain. The vertical face may comprise one or more vertical indentations to channel the liquid.

[0071] FIG. 3 A and FIG. 3B show an embodiment comprising a centrifugal pump that is driven by stators mounted on an outside wall of the cleaning well. The impeller of the centrifugal pump is driven by a spindle having a magnet fixed thereto. The electromagnetic field turns the magnet, which in turn rotates the impeller.

[0072] FIG. 4A and FIG. 4B show an embodiment comprising an axial flow pump that is driven by stators mounted within an underlying structure. The spindle of the axial flow pump is fixed to a magnet which is acted upon by the stators so as to rotate the impeller.

[0073] FIG. 5 shows an embodiment that is the same as that drawn in FIG. 4A, although with the stator coils mounted within the cleaning well. The stator coils are a conductive metal, and may be prone to oxidation or other negative effects of a liquid with which it contacts. Accordingly, the stator coils may be coated with an electrically and magnetically inert material. For example, the coating may be achieved by plastic dipping. Insulated conductors connecting the stator coils to an external power supply may be provided.

[0074] While the present disclosure is made by reference to a pipette (as a type of probe) of a sample transport system for a laboratory autosampler, further applications present. The disclosuremay be applied toother types of probe that require washing as a part of a workflow in a laboratory autosampler or any other type of equipment of an analytical laboratory, including a temperature probe, an electrode, a pH electrode, a conductivity probe, a mixing device, and a reagent dispenser.

[0075] It should be understood that the foregoing description is only illustrative of the aspects of the present disclosure. Various alternatives and modifications can be devised by those skilled in the art without departing from the aspects of the present disclosure. Accordingly, the aspects of the present disclosure are intended to embrace all such alternatives, modifications and variances that fall within the scope of any claims appended hereto. Further, the mere fact that different features are recited in mutually different dependent or independent claims does not indicate that a combination of these features cannot be advantageously used, such a combination remaining within the scope of the aspects of the present disclosure.

[0076] Any single feature or combination of features described herein may be implemented not only with the preferred embodiments disclosed herein, but also any other embodiment falling within the ambit of the present disclosure.

Claims

CLAIMS:

1. A probe washing system for use in a wash station of an automated laboratory system, the system comprising: a probe cleaning well configured to receive a probe, and comprising an inlet to admit a probe cleaning liquid; a magnetically active liquid mover disposed within the probe cleaning well, the liquid mover configured to draw a probe cleaning liquid through the inlet and into the probe cleaning well; and a magnetically active driver configured to magnetically couple with the liquid mover and to cause movement thereof, wherein movement of the liquid mover draws the probe cleaning liquid through the inlet and into the probe cleaning well so as to be contactable to a probe received therein.

2. The system of claim 1, wherein the magnetically active driver comprises a magnetic field generator configured to receive electrical power and generate a magnetic field thereabout, the magnetic field configured to move the liquid mover.

3. The system of claim 1 or claim 2, wherein the magnetic field generator is isolated from the interior of the probe cleaning well.

4. The system of any one of claims 1 to 3, wherein the magnetic field generator is disposed inside the probe cleaning well and has a coating or a housing to effect the isolation.

5. The system of any one of claims 1 to 4, wherein the magnetic field generator is disposed outside the probe cleaning well.

6. The system of any one of claims 1 to 5, wherein the magnetic field generator is disposed beneath a surface supporting the probe cleaning well.

5. The system of any one of claims 1 to 6, wherein the magnetic field generator functions as a stator, and the liquid mover functions as a rotor.

6. The system of any one of claims 1 to 7, wherein the liquid mover comprises a plurality of blades configured to move the liquid.

7. The system of any one of claims 1 to 8, wherein the liquid mover is configured for rotary or non-rotary motion.

8. The system of any one of claims 1 to 7, wherein the liquid mover is an impeller.

9. The system of any one of claims 1 to 8, wherein the liquid mover comprises one or magnets, and the one of more magnets are isolated from the interior of the probe cleaning well.

10. The system of claim 9, wherein the isolation is provided by a coating on, or a housing about, the liquid mover.

11. The system of any one of claims 1 to 10, wherein the liquid mover is disposed in a lower region of the probe cleaning well.

12. The system of any one of claims 1 to 11, wherein the probe cleaning well has a vertical axis, and the liquid mover draws the liquid at an angle to, or generally orthogonal to, the vertical axis, and directs the liquid generally upwardly along the vertical axis.

13. The system of any one of claims 1 to 12, comprising an effluent collector configured to receive cleaning fluid that has contacted a probe received in probe cleaning well.

14. The system of any one of claims 1 to 13, configured such that actuation of the liquid mover causes overflow of cleaning liquid from the probe cleaning well.

15. The system of any one of claims 1 to 14, configured such that probe cleaning liquid overflowing from the probe cleaning well enters an effluent collector.

16. The system of claim 15, wherein the effluent collector is continuously or periodically drained so as to be capable of receiving overflow from the probe cleaning well.

17. The system of any one of claims 1 to 16, configured to be alternately mountable on, and demountable from, a support surface.

18. A wash station comprising the system of any one of claims 1 to 17.

19. An automated laboratory system comprising the wash station of claim 18.

20. A method of washing a probe, the method comprising actuating the magnetically active driver of the probe washing system of any one of claims 1 to 17 so as to draw a probe cleaning liquid into the probe cleaning well, wherein the probe cleaning liquid contacts a probe disposed within the probe cleaning well.

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