This application claims priority from South African provisional patent application number 2021/06784 filed on 14 Sep. 2021, which is incorporated by reference herein.
This invention relates to a device for extracting sample material from a nucleic acid amplification cartridge.
Nucleic acid amplification is a crucial technique used in the fields of molecular biology, diagnostics, and biotechnology. For example, nucleic acid amplification can be used in diagnostics to detect the presence of pathogens, such as viruses, bacteria and fungi.
A GeneXpert test is a test which utilizes nucleic acid amplification in order to detect the presence of genetic material or organisms of interest. The GeneXpert diagnostic platform is widely used throughout the world, for rapid molecular diagnosis. GeneXpert tests utilize disposable cartridges which are placed into a machine in which nucleic acid amplification takes place. Cartridges are manufactured to be disease-specific, in order to identify and quantify the presence of a specific pathogen of interest and/or detect potential drug-resistance. In use, a sample to be tested is pipetted into the cartridge, after which the cartridge is placed in a GeneXpert™ machine where various reactions, including nucleic acid amplification, take place. These cartridges include a reaction tube, into which an amplified sample is moved so that the presence of a gene of interest may be detected. The cartridges are single use, and following the reaction of the GeneXpert test, the cartridge and the amplified sample are both discarded.
The GeneXpert test is commonly used in diagnostics and for the detection of pathogens in human patients. For example, the GeneXpert is commonly used to detect the presence of Mycobacterium tuberculosis, the bacteria responsible for causing tuberculosis (TB) in humans. To diagnose TB using the GeneXpert, a patient provides a sputum sample which is treated with sample reagent and pipetted into the cartridge. The cartridge is then inserted into a GeneXpert machine where nucleic acid amplification and purification takes place. The purified sample is ultimately moved to the reaction tube, where the presence of M. tuberculosis and resistance to rifampicin may be detected. If M. tuberculosis is detected, it can be confirmed that the patient is indeed positive for TB. The cartridge and resultant fluid are then discarded.
As is often the case with diagnostics, a medical practitioner may need to perform further tests on the patient, for example, to determine the presence of further pathogens, for drug susceptibility testing and for strain typing. As the purified sample is discarded together with the cartridge, the practitioner will then need to ask the patient to return to give further samples. This process wastes time and costs for all parties involved, and may cause delays in treatment planning, which is especially problematic for severely ill patients. Furthermore, asking contagious patients to return to testing facilities provides further risks for spreading communicable diseases to any person in contact with the patient, and a risk to the patient of contracting a further infection from other patients with whom the former will inevitably come into proximity at a clinic.
Additionally, molecular work other than diagnostics, which also utilizes nucleic acid amplification cartridges, could benefit from downstream applications using resultant amplified samples.
Therefore, it would be useful to be able to extract the purified sample from the reaction tube before discarding the cartridge, for use in downstream applications.
Currently, there are no methods used in practice to safely and aseptically extract purified samples from a reaction tube of a GeneXpert cartridge. The applicant believes that there is scope for improvement.
The preceding discussion of the background to the invention is intended only to facilitate an understanding of the present invention. It should be appreciated that the discussion is not an acknowledgment or admission that any of the material referred to was part of the common general knowledge in the art as at the priority date of the application.
In accordance with this invention there is provided an extraction device assembly for extracting a sample from a sample-containing chamber of a nucleic acid amplification cartridge, the assembly comprising:
These features may enable a sample-containing chamber of a nucleic acid amplification cartridge to be safely fit into the receptacle, with the apertures being configured to accurately align with the relevant sample-containing chamber to ensure that the liberated sample feeds directly to the collector. This may reduce the likelihood of spillage, which may cause contamination of the environment with genomic material as well as loss of the sample.
In some embodiments, the collector may comprise a tube connector arranged to releasably secure a reaction tube thereto such that the liberated sample feeds directly into and is collected by the reaction tube via the collector. Alternate embodiments may provide for the collector to comprise a collection vessel integrally formed within the cartridge interface, wherein the collection vessel is in fluid communication with the collection interface aperture, or wherein the collection interface aperture forms an opening of the collection vessel.
The cartridge interface and collection interface may be separate parts.
The assembly may include a base configured to enable the cartridge interface and collection interface to be removably secured thereto at assigned securing positions. The base may be configured to be secured to a nucleic acid amplification cartridge, with the securing positions for the cartridge interface and collection interface being positioned such that the sample-containing chamber fits into the receptacle when the base is secured to the cartridge. The base may include at least one claw arranged to grip onto the cartridge when the base is secured to the cartridge.
These features may enable the base to be secured to the cartridge, which may promote safe disposal.
The assembly may include a piercing tool with a tip complementarily shaped to the cartridge interface aperture enabling it to pass there through, and having a shaft with a smaller width than the tip, the tip further shaped to form a complementary fit with the collection interface aperture, wherein the assembly is operable to fit the sample-containing chamber in the receptacle of the cartridge interface, guide the piercing tool through the cartridge interface aperture to pierce the sample-containing chamber and lodge in the collection interface aperture to at least partially conceal the contaminated tip, liberate a sample contained therein such that the liberated sample is collected into the reaction tube, and remove the collection interface and piercing tool lodged therein from the assembly with the shaft of the piercing tool passing through a hole in the cartridge formed by the tip.
These features may enable the piercing tool to pierce the complimentarily shaped sample-containing chamber and then lodge in the collection interface aperture, both concealing the contaminated tip and temporarily plugging the reaction tube. The shaft of the piercing tool having a smaller width may enable it to pass feely through the pierced cartridge and reducing the likelihood of it being contaminated.
The extraction device assembly may be configured to extract a sample from the sample-containing chamber of a GeneXpert™ nucleic acid amplification cartridge. The cartridge interface apertures may be shaped to correspond to a shape and sidewalls of the GeneXpert™ sample-containing reaction chamber that protrudes from the cartridge.
In some embodiments, the cartridge interface apertures may have a substantially rectangular shape, substantially corresponding to a shape of sidewalls of a particular GeneXpert™ nucleic acid amplification cartridge sample-containing reaction chamber, that protrudes from the cartridge and of which the sidewalls have a substantially square shape. The piercing tool may have a substantially pyramid-shaped tip, with the base of the pyramid-shaped tip having a rectangular shape substantially corresponding with that of the GeneXpert™ sample-containing reaction chamber. The term “rectangle” refers to the more generic definition, which includes both unequal adjacent sides, as well as equal adjacent sides (i.e. a square).
The substantially pyramid-shaped tip of the piercing tool may have four faces corresponding to the four sides of the rectangular-shaped base. These four faces may each have a concave surface. This may promote effective liberating of the sample from the sample-containing chamber.
In an alternative embodiment the cartridge interface apertures may have a substantially circular shape, substantially corresponding to a shape of sidewalls of another particular GeneXpert™ nucleic acid amplification cartridge sample-containing reaction chamber, that protrudes from the cartridge and of which the sidewalls have a substantially circular shape. The piercing tool may have a substantially cone-shaped tip, with the base of the cone-shaped tip having a circular shape substantially corresponding with that of the GeneXpert™ sample-containing reaction chamber. The face of the substantially cone-shaped tip of the piercing tool may have a concave surface
These features may enable the extraction device to be used with the GeneXpert™ cartridge, with the piercing tool being shaped to breach substantially the entire area of sidewalls of the cartridge, thereby promoting the liberating of the sample. These features may correspond to the shape of the sidewalls of the GeneXpert™ sample-containing reaction chamber that protrudes from the cartridge and may not be limited to a specific shape.
The tube connector may be arranged to releasably secure a microcentrifuge tube thereto. The tube connector may be arranged to releasably secure a PCR tube having a capacity of between 0.1 mL and 0.5 mL, preferably about 0.2 mL.
Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings.
In the drawings:
An exemplary embodiment of an extraction device assembly is described below. The extraction device assembly finds particular application in the extraction of material from a nucleic acid amplification cartridge. More specifically, extraction of material from a sample-containing chamber of a nucleic acid amplification cartridge, such as a GeneXpert™ nucleic acid amplification cartridge.
The extraction device assembly includes a cartridge interface and a collection interface. The cartridge interface includes a receptacle (or cradle) configured to at least partially fit a sample-containing chamber of a nucleic acid amplification cartridge therein. The cartridge interface includes an aperture which is configured to at least partially expose the sample-containing chamber when it is fitted in the receptacle. That is to say that the aperture allows (at least partial) access to the sample-containing chamber. The collection interface also includes an aperture configured to at least partially align with the cartridge interface aperture, with the sample-containing chamber being positioned at least partially between the cartridge interface aperture and collection interface aperture when fitted in the collection receptacle. The cartridge interface therefore cradles the cartridge such that its sample-containing chamber is sandwiched between the cartridge interface chamber and the collection interface aperture.
The collection interface includes a collector which is configured to be in fluid communication with the sample-containing chamber, via the collection interface aperture. The collection interface aperture is therefore an opening leading to the collector.
The cartridge interface aperture is used to guide a piercing tool to breach at least one wall of the sample-containing chamber and liberate a sample contained therein such that the liberated sample is transferred to the collector. The sample-containing chamber of the GeneXpert™ cartridge, for example, is a substantially rectangular (or square) chamber protruding outward from the main body of the cartridge and having two relatively thin plastic walls with the space between the walls forming a reservoir in which the sample may be contained. When the extraction device assembly is used with the GeneXpert™ cartridge, the cartridge interface aperture is used to guide the piercing tool to breach both walls of the sample-containing chamber and liberate the sample contained therein such that the liberated sample is transferred to the collector.
The collector may comprise a tube connector arranged to releasably secure a reaction tube to the collector, such as a microcentrifuge tube. Once the liberated sample has been collected in the reaction tube, it may therefore be removed from the extraction device assembly and the sample can be used in further applications. Alternate embodiments may provide for the collector to be a collection vessel which is integrally formed with the collection interface. The sample can then be removed from the collection vessel, by means of a pipette, or the like, for use in further applications.
The extraction device assembly may also include a base which enables the extraction device assembly to be secured onto the nucleic acid amplification cartridge. The cartridge interface and the collection interface may be removably secured to the base. The base may include at least one claw arranged to grip onto the cartridge, when the base is secured to the cartridge. The claw or claws may be located at the ends of elongate, tensile arms. As the base is secured to the cartridge, the claws may be forced open, and clamp onto features of the cartridge under the force of the tensile arms.
Furthermore, the extraction device assembly may also include a piercing tool which can be used to pierce the sample-containing chamber, when the cartridge interface and collection interface are fitted onto the cartridge. The piercing tool may be configured to pass through the aperture of the cartridge interface and lodge into the aperture of the collection interface. This may allow the piercing tool to pierce the sample-containing chamber and pass therethrough, whilst blocking the opening of the collection interface so as to maintain a sterile environment within the collector.
The extraction device assembly may therefore be fitted onto the sample-containing chamber of a nucleic acid amplification cartridge. A piercing tool may then be used to puncture at least a part of the sample-containing chamber to liberate a sample contained therein. The liberated sample may then feed directly into the collector. This allows for the aseptic collection of the contents of the sample-containing chamber, for possible use in further downstream applications.
As mentioned above, the extraction device assembly may have particular application for use with a GeneXpert™ nucleic acid amplification cartridge. Therefore, the extraction device assembly may be used to extract a sample contained in a sample-containing chamber of a GeneXpert™ nucleic acid amplification cartridge.
The term “nucleic acid amplification cartridge” used herein refers to a cartridge for use in molecular work. Specifically, it refers to a cartridge into which a sample may be inserted in order to amplify genetic material of interest which may be contained in a sample, by polymerase chain reaction (PCR). Also, the term “sample-containing chamber” of a nucleic acid amplification cartridge used herein refers to an output chamber of a nucleic acid amplification cartridge into which a processed and amplified sample is transferred. This is typically an external chamber of the cartridge, configured to be relatively thin in shape, with thin walls.
Embodiments of the invention will now be described with reference to the accompanying drawings, by way of example only.
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The extraction device assembly (1) in
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The base (25) is also a separate component of the extraction device assembly (1). This is best illustrated in
After use, a nucleic acid amplification cartridge is typically disposed of. The claw arrangement of the base allows for the convenient and safe disposal of both the extraction device assembly, or at least certain components thereof (such as the base), together with the nucleic acid amplification cartridge.
The extraction device assembly (1) includes a piercing tool (17), as is illustrated in
As is shown in
Therefore, when the sample-containing chamber (3) is fit into the receptacle (9) of the cartridge interface (7), the piercing tool (17) is pushed into the cartridge interface aperture (11) by hand and guided through the cartridge interface aperture (11) to breach at least one wall of the sample-containing chamber (3) through the force applied by an operator's hand on back of the piercing tool shaft (31). Optimally, as is the case in this embodiment, the piercing tool (17) will bisect a width of the sample-containing chamber (3) to liberate the sample contained therein. At least some of the sample will then flow into the reaction tube (23), via the collection interface aperture (15). The tip (29) of the piercing tool (17) will then be lodged into the collection interface aperture (15) so that the contaminated tip (29) is at least partially concealed therein. The collection interface (13) can then be removed from the rest of the extraction device assembly (1), together with the piercing tool (17) lodged therein. The liberated sample will therefore be securely held within the reaction tube (23).
The nucleic acid amplification cartridge (5) may be a GeneXpert™ nucleic acid amplification cartridge for use in GeneXpert™ systems. The GeneXpert™ cartridge includes a sample-containing chamber which extends out of a front side of the cartridge. The sample-containing chamber is typically of a flat, rectangular or square in shape with a pointed distal end, as is illustrated in the accompanying Figures of the exemplary embodiment. In any embodiment in which the nucleic acid amplification cartridge is a GeneXpert™ cartridge, the cartridge interface apertures will have substantially rectangular or square shapes, corresponding to the shape of the GeneXpert sample-containing chamber. The piercing tool will therefore have a pyramid-shaped tip with a rectangular or square concave shape substantially corresponding to the shape of the GeneXpert™ sample-containing reaction chamber.
The extraction device assembly (1) is first assembled, prior to use. This entails connecting the cartridge interface (7) and the collection interface (13) to the base (25), as illustrated in step A.
The GeneXpert cartridge (5) is connected onto the base (25) such that the claws (27) of the base grip tightly onto the cartridge (5), as is illustrated in step B. A reaction tube (23) is then connected to the tube connector (21) of the collection interface (13), as is shown in step C. The extraction device assembly (1), together with the cartridge (5) is tilted onto their side, and the piercing tool (17) is pressed into the cartridge interface aperture (11) by hand and guided through the cartridge interface aperture (11). The operator applies pressure by hand onto the back of the shaft (31) of the piercing tool (17), in a downwards direction (X), to break through the sample-containing chamber (3) and lodge into the collection interface aperture (15), illustrated in step D.
The collection interface (13) is then removed from the assembly (1) by sliding the lodged piercing tool (17) through the cartridge interface aperture (11). Whilst an operator grips the piercing tool (17) together with the collection interface (13) and the reaction tube (23), these components should be given an up-and-down shake to encourage sample material to flow downwards into the bottom of the reaction tube (23), in the direction indicated as X. The reaction tube (23) can then be removed from the tube connector (21) and centrifuged to ensure all sample material is in the bottom of the reaction tube (23).
Following extraction, the components of the extraction device (1) can then be discarded to minimize contamination of the environment with genomic material.
The piercing tool (117) of
Another example embodiment of a base (125) is shown in
The extraction device assembly therefore allows a processed sample of a nucleic acid amplification cartridge, which would previously have merely been discarded, to be used in further downstream applications. The assembly allows for the aseptic extraction of the sample from the cartridge, which prevents any pathogens from being released from the sample, or any material cross-contaminating the sample.
The foregoing description has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure.
The language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention set forth in any accompanying claims.
Finally, throughout the specification and any accompanying claims, unless the context requires otherwise, the word ‘comprise’ or variations such as ‘comprises’ or ‘comprising’ will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
Number | Date | Country | Kind |
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2021/06784 | Sep 2021 | ZA | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2022/058615 | 9/13/2022 | WO |