SAMPLE PREPARATION SYSTEM AND CARTRIDGE
20190270086 ยท 2019-09-05
Inventors
- Piers Sebastian Harding (Royston, Hertfordshire, GB)
- Gary Stephen HOWARD (Royston, Hertfordshire, GB)
- Gary Keith Jepps (Royston, Hertfordshire, GB)
Cpc classification
B01L2300/021
PERFORMING OPERATIONS; TRANSPORTING
C12N15/1003
CHEMISTRY; METALLURGY
B01L3/021
PERFORMING OPERATIONS; TRANSPORTING
B01L2200/141
PERFORMING OPERATIONS; TRANSPORTING
B01L7/52
PERFORMING OPERATIONS; TRANSPORTING
G01N35/00732
PHYSICS
B01L2200/04
PERFORMING OPERATIONS; TRANSPORTING
B01L2200/0684
PERFORMING OPERATIONS; TRANSPORTING
B01L2200/0647
PERFORMING OPERATIONS; TRANSPORTING
G01N35/0098
PHYSICS
B01L2300/0867
PERFORMING OPERATIONS; TRANSPORTING
B01L2300/044
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A sample preparation cartridge for use with a sample preparation device, the cartridge includes a housing defining plural separate segments, at least one of said segments comprising a fixed section of a pipette component; and a moveable head comprising a pipette tip, the head being configured, in use, to be moved between a position in which the pipette tip is in sealed engagement with the fixed section of pipette component and a position in which pipette tip is positioned adjacent to another of said plural segments. With the present invention a disposable sample preparation cartridge and corresponding analytical reader can be provided in a very cost effective and simple manner whilst still ensuring high quality sample preparation for analysis.
Claims
1. A sample preparation cartridge for use with a sample preparation device, the cartridge comprising: a housing defining plural separate segments, at least one of said segments comprising a fixed section of a pipette component; and a moveable head comprising a pipette tip, the head being configured, in use, to be moved between a position in which the pipette tip is in sealed engagement with the fixed section of pipette component and a position in which pipette tip is positioned adjacent to another of said plural segments.
2. A sample preparation cartridge according to claim 1, where at least one of the segments has a fluid seal and the moveable head further comprises a piercing component arranged to pierce the seal when the head is moved to the respective segment.
3. A sample preparation cartridge according to claim 1, wherein the segments are arranged around a central axis of the housing and the moveable head is arranged to rotate around the axis and lower towards, or raise from, a desired segment when it has been rotated to be positioned above the desired segment in use.
4. A sample preparation cartridge according to claim 3, further comprising a shaft attached to the head and positioned at the central axis, the shaft being arranged to engage, in use, with a drive member in an analytical reader of the sample preparation device when the sample preparation cartridge is inserted therein so that the drive member can move the shaft and the head, the shaft comprising a passageway for allowing fluid communication between the pipette and the analytical reader.
5. A sample preparation cartridge according to claim 4, wherein the shaft further comprises a vent to allow the interior of the housing to be balanced to atmospheric pressure.
6. A sample preparation cartridge according to claim 4 or 5, wherein the passageway comprises a filter to prevent contamination.
7. A sample preparation cartridge according to claims 3 to 6, the plural separate segments containing analytes and/or beads or capture filters in use, wherein the pipette tip is arranged to transfer, in use, analytes and/or beads or capture filters from one segment to another in order to prepare a sample for analysis, wherein the pipette tip further comprises: a reservoir section capable of supporting fluids, and a nozzle section capable of dispensing and aspirating fluids from the segments; and the pipette is pneumatically connected to a programmable control system for providing positive and negative flow of air through the pipette in use.
8. A sample preparation cartridge according to claim 7, wherein the movable pipette tip can be selectively positioned relative to one of the selected segments.
9. A sample preparation cartridge according to claim 7, wherein the pipette tip is configured to aspirate and dispense and the fixed section of the pipette component provides a fluid path into the respective segment.
10. A sample preparation cartridge according to any of claim 7, wherein the movable pipette tip comprises a reservoir and filter to reduce contamination.
11. A sample preparation cartridge according to claim 7, wherein the moveable head comprises a piercing component that pierces a breakable seal of a segment during engagement of the pipette tip with the fixed section of pipette to allow the air pressure within the segment to equalise during aspiration and dispensing.
12. A sample preparation cartridge according to claim 11, wherein the head is configured to provide a rotary movement such that the piercing component can produce an elongated hole that does not seal around the piercing component in use.
13. A sample preparation cartridge according to claim 11, wherein the pipette tip is non-circular so as not to produce a seal with the breakable seal during insertion.
14. A sample preparation cartridge according to claim 7, wherein, in use, the shaft further provides a pneumatic engagement between the pipette tip and the analytical reader to provide a means of controlling the pressure within the pipette.
15. A sample preparation cartridge according to claim 1, further comprising an area that the moveable pipette tip can be lowered onto to remove excess residue from the pipette tip.
16. A sample preparation cartridge according to claim 1, further arranged to fill a reaction vessel with fluid in use, for analysis, using the pipette tip and further comprising a hydrophobic filter to produce a pressure in the reaction vessel that causes an outer face of the reaction vessel to deform and provide a good thermal contact with a thermal block engaged therewith.
17. A sample preparation cartridge according to claim 1, wherein the housing comprises: a lower tray which defines the plurality of separate segments; and an upper cover; wherein the lower tray is constructed from a single plastic moulding or separate segments
18. A sample preparation cartridge according to claim 17, wherein the lower tray has a separate plug-in cartridge having a plurality of chambers suitable for storing solid, dried or liquid substances.
19. A sample preparation cartridge according to claim 17, wherein the housing comprises a sealable door for receiving a sample in use.
20. A sample preparation cartridge according to claim 1, claim wherein at least one segment contains reagents and at least one segment contains paramagnetic beads.
21. A sample preparation cartridge according to claim 20, wherein the segment containing paramagnetic beads has a tapering V-shaped floor so as to provide a drainage point to extract fluids.
22. A sample preparation cartridge according to claim 20, further comprising: an arrangement of magnets moveable to a position, in use, where their magnetic field attracts the paramagnetic beads to surfaces of the segment, the magnets and segment being arranged such that they can be used to provide a zone clear of paramagnetic beads for the pipette tip to aspirate fluid from the segment; and that by aspirating fluid from the segment thus, bringing beads closer to the magnetic field and increase the rate of bead capture.
23. A sample preparation cartridge according to claim 22, wherein the segment and magnets are arranged to provide the zone clear of beads at the lowest point in the segment.
24. A sample preparation cartridge according to claim 1, claim further comprising a coded tag.
25. A sample preparation cartridge according to claim 24, wherein the coded tag comprises a barcode.
26. A sample preparation cartridge according to claim 24, wherein the coded tag comprises an RFID chip.
27. A sample preparation cartridge according to claim 24, wherein the coded tag comprises a communication interface operable to convey real time information between the cartridge and an instrument into which the cartridge can be removably inserted.
28. A sample preparation cartridge according to claim 1, wherein plural segments each has a respective fixed section of pipette component.
29. A sample preparation cartridge according to claim 1, wherein at least one of the segments comprises components for preparation of the sample.
30. A sample preparation cartridge according to claim 1, wherein the segments can be filled, via the fixed pipette section, with fluids to a level with virtually no head space prior to sealing with foil or other method.
31. An analytical reader comprising: means for receiving a sample preparation cartridge for use with a sample preparation device, the cartridge comprising: a housing defining plural separate segments, at least one of said segments comprising a fixed section of a pipette component; and a moveable head comprising a pipette tip, the head being configured, in use, to be moved between a position in which the pipette tip is in sealed engagement with the fixed section of pipette component and a position in which pipette tip is positioned adjacent to another of said plural segments; and drive means for engaging with the sample preparation cartridge to move the head in use.
32. (canceled)
33. A sample preparation system comprising a plurality of fixed segments containing analytes and/or beads in use and a moveable pipette positioned above the segments, wherein the pipette is arranged to transfer, in use, analytes and/or beads from one segment to another in order to prepare a sample for analysis, wherein the pipette comprises: a reservoir section capable of supporting fluids, and a nozzle section capable of dispensing and aspirating fluids from the segments; a central shaft and drive mechanism, wherein the pipette is connected to the central shaft, where the shaft is connected to a drive system so that it can move the pipette in a rotary direction to a programmable position and a vertical direction to a programmable position; and the pipette is pneumatically connected to a programmable control system for providing positive and negative flow of air through the pipette in use.
34. The sample preparation system of claim 33, wherein the pipette is formed in two parts with a moving part that can rotate, move up and down and aspirate and dispense, and a fixed part that provides a fluid path into a chamber.
35. The sample preparation system of claim 33, further comprising the cartridge of any of claims 1 to 30.
36. A method for separating a desired analyte from a sample, the method comprising the steps of: introducing a sample to a chamber, the chamber containing paramagnetic particles configure to capture nucleic acid; repeatedly aspirating and dispensing fluid into the chamber so as to cause fluid movement within the chamber; capturing nucleic acid in the sample using the paramagnetic beads; and applying a magnetic field to the chamber.
Description
[0014] Examples of the present invention will now be described with reference to the accompanying drawings in which:
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[0028] Referring to
[0029] As can be seen from
[0030] As can also be seen in
[0031] When in the lowered position tip 6 engages and fluidly seals with the mouth of fixed part of the pipette 8 positioned within a segment 31, 32, 33.
[0032] In use the sample preparation cartridge 1 is opened by a user and a sample placed within the sample preparation cartridge 1 via the door 2. The door 2 is then closed and the sample preparation cartridge 1 is inserted into the analytical reader 3. The drive member 4 from the analytical reader 3 is raised to engage with the shaft 5 of the sample preparation cartridge 1. The pipette arm 14 can then be rotated to its desired position above a desired segment within the sample preparation cartridge 1. The pipette arm 14 can then be lowered, with the spike 12 piercing any sealing member 11 as lowering occurs, to provide a vent hole in the sealing 11 of the segment 31, 32, 33. Rotary movement of the pipette tip 6 at this stage will widen the spike hole to ensure that venting occurs. The pipette arm 14 and its tip 6 can then engage with any fixed section of pipette 8 in a particular segment 31, 32, 33. The tip 6 of the pipette engages with the fixed section of the pipette 8 in the segment to provide a fluid seal and allow any fluid 10 in the desired segment to be drawn up via the tip 6 into the pipette arm 14. The fluid can, if desired be drawn into the analytical reader of the sample preparation device 3, or may alternatively be held within the pipette arm 14 whilst it is then raised, rotated and lowered into another desired segment chamber 31, 32, 33 where further processing may occur. The other desired segment may contain other analytical substances, or as shown in
[0033] As will be appreciated, there are a number of sample preparation techniques and analytical approaches that the sample preparation cartridge 1 and analytical reader 3 of the sample preparation instrument according to the invention can be configured to follow dependent upon the information required in respect of an individual patient. In one example a sample can be provided which is then lysed and then mixed with paramagnetic particles to provide magnetic bead separation of target entities which will be described in more detail in reference to the further embodiments of the current invention below.
[0034]
[0035] The lower tray 17 contains a plurality of formed segments 31, 32, 33 which provide chambers used to store, contain and process the sample. The geometry of each chamber 31, 32, 33 is preferably wedge or cone shaped, with a tapering V shaped floor 34 so as to provide an effective drainage point to extract fluids 10. Chambers 31, 32, 33 can be covered by a breakable cover seal 11, such as a foil seal to prevent spillage in transit and increase the shelf life of the reagents. The upper cover 27 can carry a machine-readable identification coded tag, such as a 2D bar code 50, RFID chip or other optical, magnetic or near-field wireless interface for conveying data that can be read by the reader. The coded tag can convey data identifying the nature of the cartridge 1 and the assays, steps or tests contained therein. The coded tag can convey specific instructions to the analytical reader of the device 3. For example a cartridge 1 comprising a new test may be launched on the market after the introduction of the system and the coded tag can be used to advise the instrument 3 of specific temperature cycling requirements. Alternatively or additionally the coded tag may be used to advise the analytical reader of the instrument 3 of time periods, such as settling times during sample aspiration for example. The coded tag may further convey traceability and/or tracking information as well as other useful parameters such as expiry date. The data and instructions encoded on the coded tag may be used automatically by the instrument 3, and may be done so selectively either with or without user intervention, to deliver a number of enhanced system benefits, safety and efficacy warnings, and/or usability features. The coded tag 50 may incorporate active communication such that status or error messages can be conveyed between cartridge 1 and instrument 3.
[0036] After the sample is introduced and sealed within the cartridge 1, the cartridge 1 is inserted into the analytical reader of the sample preparation instrument 3 where a central drive shaft 35 of the drive member 4 of the analytical reader 3 is raised to mechanically and pneumatically engage with the movable pipette tip 6 via the shaft 5. The mechanical coupling is designed to allow the instrument to selectively move the pipette tip 6, and in this embodiment includes a hexagon shaped drive shaft 35 that locates into a tapering hexagonal hole 24 in the pipette's central shaft 5 so as to provide a means to transfer rotary and vertical motion to accurately control the position of the movable pipette 6. The hexagon arrangement allows for ease of engagement; however other shaft profile shapes could be used. The drive shaft 35 includes a split-ring 36 that locates in a recess 40 in the pipette central shaft 5 to provide a positive mechanical coupling during vertical movement of the shaft 5.
[0037] The coupling arrangement also includes an O-ring 37, mounted on the drive shaft 35 that pneumatically seals against the inside face of the pipette's central shaft 5 during engagement of the drive shaft 35 into the moveable pipette tip 6.
[0038] Alternative drive configurations are possible. For example, the drive shaft 35 may be incorporated within the cartridge 1, and a gear or set of teeth located at its lower edge to interlock with a complementary gear or teeth arrangement located within the instrument 3. Alignment sensors may be incorporated into the drive shaft 35, hole 24 or elsewhere that may be used to convey, via an active coded tag, the current status of the cartridge 1 to the analytical reader of the sample preparation instrument 3.
[0039] A movable pipette 6 is used to manipulate fluids within the chambers 31, 32, 33 in the lower tray 17. The pipette includes a moveable pipette tip 6, a reservoir 18, connected to a central shaft 5 and is selectively connected to a plurality of fixed pipette nozzle parts 8; one located in each chamber 31, 32, 33. The fixed nozzles 8 are positioned so that their tips 71 are at the lowest point of each chamber 31, 32, 33 to enable extraction of the maximum amount of fluid 10 from each chamber 31, 32, 33.
[0040] The geometry of the apparatus allows the instrument 3 to selectively determine the rotary and vertical position of the movable pipette tip 6 relative to the lower tray 17 with segmented chambers 31, 32, 33, containing the reagents.
[0041] The movable pipette tip 6 can be aligned, by pre-determined programming of the instrument 3 and in particular the control of the central drive coupling 35, above the desired fixed part of the pipette 8 and lowered into the chamber 31, 32, 33, breaking through a breakable seal 11 (if this has not already been broken). The mechanical coupling of the moveable pipette tip 6 and the fixed pipette portion 8, together with the pneumatic connection to the instrument allows fluid to be aspirated or dispensed from or to selected chambers 31, 32, 33 within the lower tray 17 or the reaction chamber 22.
[0042] Some of the sample preparation process steps are highly sensitive to carry-over of fluid residue from previous transfer steps, consequently, the lower tray 17 includes an area 51 containing wadding, paper or other means, such as mould texture or pattern, that the movable pipette tip 6 can be lowered onto, to remove excess residue from the pipette tip 6.
[0043] The internal volume of the movable pipette reservoir 18 and the programmable pneumatic system ensures that fluid can be transferred by the movable pipette 6 without the need for liquid to flow through the passageway 16 of the movable pipette's central shaft 5, into the instrument 3. A filter 15 between the movable pipette reservoir 18 and pneumatic supply prevents airborne particles from the cartridge 1 contaminating the pneumatic system within the instrument 3.
[0044] To prevent air lock within the chambers 31, 32, 33, the movable pipette tip 6 includes a piercing member such as a spike 12 that pierces the selected chambers breakable seal 11 prior to movable pipette tip 6 engaging with the fixed part of the pipette 8. The spike's 12 function is to provide a vent through the breakable seal 11 and as such it is located away from the movable pipette tip 6. The vent may be achieved by rotary movement of the movable pipette 6 to form an elongated hole that does not seal around the spike 12. Alternatively, the geometry of the spike 12 can be non-circular so as to prevent it sealing against the breakable seal 11 during insertion.
[0045] A filtered breather vent 51, shown here as comprised within the upper cover 27 ensures that the pressure in the cartridge 1 can equalise with ambient during operation. This prevents the risk of the cartridge 1 becoming pressurised and potentially contaminating the instrument 3. The filtered breather vent 51 can be held in place, for example, by an identification label 50.
[0046] Mixing of fluids within chambers 31, 32, 33 can be promoted by repeatedly aspirating and dispensing fluid into the pipette tip 6 so as to cause rapid fluid movement within the chamber 31, 32, 33. This yields fast and comprehensive mixing at lower overall system cost than the possible alternatives such as vibrating or agitating the cartridge 1.
[0047] The pipetting arrangement allows for a solution of paramagnetic particles or beads 54 to be used to capture nucleic acid in the sample, and the paramagnetic particles 54 can be subsequently washed to remove unwanted substances whilst retaining the nucleic acid for subsequent treatment or release, according to methods well-known in the art.
[0048] Advantageously, the arrangement assumes a fixed location and includes two magnets 53, movable between a first position, where their magnetic field attracts magnetic particles to surfaces of the chamber 31, 32, 33, and a second position, where its magnetic field has substantially no effect on the magnetic particles.
[0049] When in their first position, the magnets 53 are mounted perpendicular to either side of the V shaped chamber 31, 32, 33 to provide a concentrated magnetic field 55 at either side of the chamber and a neutral particle free plane 56 between them that allows fluid, without magnetic particles, to be removed from the lowest point in the chamber 31, 32, 33, via a fixed pipette 8.
[0050] Pipetting clear fluid from the neutral particle free plane 56 allows other areas of the fluid to be bought closer to the rapid clearing zone. This arrangement can significantly increase the rate of bead capture and provides a substantial speed and efficiency benefit over prior art approaches.
[0051] Although cartridge 1 can be individually configured for specific sample and test types, some of the fluids and substances stored in the chambers 31, 32, 33 in the lower tray 17 are common to several sample types. Cost-efficiencies and shelf-life advantages may be achieved with a generic cartridge 1 that comprises just these common materials. Others might vary for different preparations and these may advantageously be provided in a separate plug-in cartridge 20, inserted into the lower tray 3, prior to use. The plug-in cartridge 20 contains a plurality of chambers 55 suitable for storing solid, dried or liquid substances and can be covered by a breakable cover seal 57, such as a foil seal or the like to prevent spillage in transit and increase the shelf life of the reagents. The plug-in cartridge 20 also contains a plurality a fixed nozzles 56 that combine with the movable pipette 5.
[0052] The plug-in cartridge 20 can be stored in a separate foil pouch, away from the liquids within the cartridge 1, which provides the benefit of longer shelf life for dried or solid reagents. The plug-in cartridge 20 can carry a machine-readable identification coded tag 58, such as a 2D bar code 50, RFID chip or other optical, magnetic or near-field wireless interface for conveying data that can be read by the reader. Coded tag 58 can convey data identifying the customised nature of the cartridge 1 incorporating the plug-in cartridge 20 including identification of the assays, steps and/or tests contained within. The coded tag can convey specific instructions to the instrument 3. For example a plug-in cartridge 20 comprising materials for a new sample and/or test may be launched on the market after the introduction of the system and the coded tag can be used to advise the instrument 3 of specific requirements, for example temperature cycling requirements. Alternatively or additionally the coded tag may be used to advise the instrument of time periods, such as settling times during sample aspiration for example. The coded tag may further convey traceability and/or tracking information as well as other useful parameters such as expiry date. The data and instructions encoded on the coded tag may be used automatically by the instrument 3, and may be done so selectively either with or without user intervention, to deliver a number of enhanced system benefits, safety and efficacy warnings, and/or usability features.
[0053] The cartridge geometry allows the plug-in cartridge 20 to be snapped into the lower tray 17, to form part of the chemistry set, accessible by the movable pipette tip 6, required to prepare the sample. Dried or solid reagents are hydrated, during operation, using the aqueous substances stored in the other chambers in the cartridge.
[0054] Once the sample has been processed, the analyte can be transferred from a chamber 31, 32, 33, using the movable pipette 6, to a reaction vessel 22 for suitable reaction, such as thermocycling for PCR.
[0055] The reaction vessel 22 is constructed from a moulded section 64, a flexible film 65 and a semi breathable vent 66. Fluid is transferred from a selected chamber 31, 32, 33 and is introduced into the reaction vessel 20 via the movable pipette tip 6. Bubbles in the reaction fluid can affect the analysis readings and the reaction vessel is designed with a geometry that ensures that bubbles are not formed during fill. A breather filter allows air to escape from the reaction vessel 22 during the fill process; however the filter is manufactured using hydrophobic material that does not allow fluid through it at the relatively low pressures provided by the instrument 3. In this way, the movable pipette tip 6 is able to produce a positive pressure in the cuvette during the reaction process which helps its thermal contact with the thermal block.
[0056] Measurement of the fluid 10 in the reaction vessel 22 can be achieved via conventional methods such as optical means, electrochemical means, electrophoresis and custom chips. In all cases the instrument interfaces with the cartridge, either optically, through transparent walls in the reaction chamber or electrically, through electrodes via pads on the cartridge.
[0057] As shown in
[0058] The cartridge has been described as comprising a pipette structure that has a moving part 6 and fixed parts 8. It should be apparent that this approach yields substantial improvements in form factor, in that the cartridge 1 can achieve a significantly lower profile than if a single-piece, movable pipette were used. However, if space is not a constraint, then the movable pipette 5 can be extended such that the movable tip 21 has sufficient length to be inserted down to the lowest point of each chamber 30, 31, 32, 55 and thus the fixed parts 8 can be eliminated from the system. This might reduce overall cost at the expense of increasing the length of central shaft 5, drive shaft 35 and the overall height of the cartridge 1.
[0059] The arrangement of the movable pipette tip 6, fixed chambers 31, 32, 33 and reagent cartridge 20 allows for a highly flexible and programmable approach that can be used for many types of diagnostic process such as Quantitative or real time PCR (thermally cycled), PCR (isothermal), immunoassay, clinical chemistry, lateral flow, and many others where samples are transferred, mixed, reacted and analysed.
[0060] With the invention a user places the sample (blood, fluid, etc.) into the sample preparation cartridge 1 and then places it in the analytical reader 3. The reader 3 engages with the sample preparation cartridge 1 (for example mechanically, pneumatically, optically, or thermally) and processes the sample in the cartridge. At the end of the processing, the reader measures the sample preparation cartridge (this could be optical or electrical) and provides a result to the user. The sample preparation cartridge 1 is then removed from the reader of the sample preparation device 3 and can be disposed of.
[0061] A compact embodiment has been disclosed wherein the cartridge is inserted in an analytical reader for processing. Alternative attachment methods and topologies will be readily apparent to the skilled person, including placing the cartridge onto an analytical instrument, or engaging the analytical reader's drive member into the cartridge using bayonet-like features.
[0062] As will be appreciated from the above, the present invention provides a simple low cost sample preparation cartridge 1 which is easy for an operator to use through simple insertion. By use of the two-part pipette configuration the overall depth of the sample preparation cartridge 1 can be reduced to keep it small and compact, low cost and easy to handle. Furthermore, by the use of filtering in the conduits of the analytical reader 3 it is possible to ensure that there is no contamination of the core analytical reader within a sample preparation device or instrument by individual samples whilst still ensuring simple operation.