Patent Application
20230330665
The present invention relates generally to the field of biochemical analysis, and in particular to sample cartridges for analyzing a fluid sample.
The analysis of fluids such as clinical or environmental fluids generally involves a series of processing steps, which may include chemical, optical, electrical, mechanical, thermal, or acoustical processing of the fluid samples. Whether incorporated into a bench-top instrument, a disposable cartridge, or a combination of the two, such processing typically involves complex fluidic assemblies and processing algorithms. Conventional systems for processing fluid samples employ a series of chambers each configured for subjecting the fluid sample to a specific processing step. As the fluid sample flows through the system sequentially from chamber to chamber, the fluid sample undergoes the processing steps according to a specific protocol.
In recent years, there has been considerable development in the field of biological testing devices that facilitate manipulate a fluid sample within a sample cartridge to prepare the sample for biological testing by polymerase chain reaction (“PCR”). One notable development in this field is the GeneXpert sample cartridge by Cepheid. The configuration and operation of these types of cartridges can be further understood by referring to U.S. Pat. No. 6,374,684 entitled “Fluid Control and Processing System,” and U.S. Pat. No. 8,048,386 entitled “Fluid Processing and Control.” While these sample cartridges represent a considerable advancement in the start of the art when developed, as with any precision instrument, there are certain challenges in regard to performance and use of such systems and processes. Moreover, the precise requirements of a particular assay and different target types (e.g. bacterial or viral) necessitates the development of cartridges that operate in a robust and consistent manner. These demands of sample cartridges, which entails fluid manipulation between various chambers and transport into a reaction chamber requires complex interaction between multiple mechanical systems.
In order to continually improve performance and increase capabilities of sample cartridges, the standard approach in the industry has been to incorporate additional componentry and mechanical systems into the existing devices. While this approach is widely used, in practice, increasing the complexity and componentry of sample cartridges presents multiple challenges in both manufacture and operation of the devices, including incompatibilities with existing interfaces, unpredictable errors and inconsistencies in performance.
Thus, there is a need for sample cartridges that maintain and/or improve performance and versatility of sample cartridge devices while simplifying the cartridge design and reduce design complexities in order to improve manufacturing and assembly and provide cartridges that operate in a more robust and consistent manner. There is further need for sample cartridges having improved design features and functionality that are compatible with existing interfaces in order to reduce costs and improve availability to patients.
The present invention pertains to sample cartridge devices and associated components, particularly sample cartridge devices capable that perform sample preparation and testing of a biological sample within the cartridge.
The present invention pertains to various improvements and features for sample cartridges having a cartridge body with multiple chambers for processing a biological sample for analysis within an attached reaction vessel. Such sample cartridges can include a syringe tube fluidically connected to a rotatable valve assembly rotation which facilitates transport of fluid sample between the chambers and reaction vessel via the syringe tube. The valve body can include a chamber in which a filter is supported, through which the biological sample is filtered, before an elution from the filter is advanced into a reaction vessel that extends from the body of the cartridge and is fluidically attached to the cartridge for analytical testing. The valve body is supported beneath the multiple chambers in a base of the sample cartridge. The sample cartridge further includes a lid that is fluidically sealed atop the multiple chambers, thereby fluidically sealing each chamber relative each other. These aspects can be further understood by referring to U.S. Pat. No. 6,374,684 entitled “Fluid Control and Processing System,” filed Aug. 25, 2000; U.S. Pat. No. 8,048,386 entitled “Fluid Processing and Control,” filed Feb. 25, 2002; and US 2017/0023281 entitled “Thermal Control Device and Methods of Use” filed Jul. 22, 2016; each of which is incorporated herein by reference in its entirety for all purposes. The sample cartridge is configured to be received within a processing module that operates the cartridge to perform sample preparation and analytical testing. The desired analyte is typically intracellular material (e.g., nucleic acid, proteins, carbohydrates, or lipids). In some embodiments, the analyte is nucleic acid which the cartridge separates from the fluid sample and holds for amplification (e.g., using PCR or an isothermal amplification method) and optical detection. It is appreciated that the invention described herein can pertain to any fluid sample cartridge having any of the above features or any combination thereof.
In one aspect, the invention pertains to a sample cartridge of a unitary design in which various components are integrally formed. In some embodiments, the cartridge design includes a unitary cartridge body having multiple chambers, a syringe tube and a base. In another aspect, the invention pertains to valve assemblies having various improvements, including any of: an overmolded gasket, a protruding non-flat gasket, a snap-fit tube mount for a reaction vessel, an inclined filter face and filter support ribs, a unitary valve assembly for chemical lysis, and thin film sealing of the cartridge lid. In yet another aspect, the invention pertains to a “no-loop” design of the sample cartridge and/or reaction vessel and methods of manufacture in which one channel is open to atmosphere or is closed and relies on pressurization of headspace for fluid flow. In yet another aspect, the invention pertains to sample cartridges and valve bodies incorporating a magnet and magnetic capture chamber for magnetic separation. Various tools and manufacturing methods are also detailed herein.
In accordance with an aspect of the invention, a fluid control and processing system comprises a housing having a plurality of chambers, and a valve body including a fluid processing region continuously coupled fluidically with a fluid displacement region. The fluid displacement region is depressurizable to draw fluid into the fluid displacement region and pressurizable to expel fluid from the fluid displacement region. The valve body includes at least one external port, the fluid processing region is fluidically coupled with at least one external port, and the fluid displacement region is fluidically coupled with at least one external port of the valve body. The valve body is adjustable with respect to the housing to allow the at least one external port to be placed selectively in fluidic communication with the plurality of chambers.
In some embodiments, the sample cartridge employs a rotary valve configuration to control fluidic movement within the cartridge that allows for selective fluidic communication between a fluid sample processing region and a plurality of chambers in the cartridge. Non-limiting exemplary chambers can include, a sample chamber, a reagent chamber, a waste chamber, a wash chamber, a lysate chamber, an amplification chamber, and a reaction chamber. The fluid flow among the fluid sample processing region and the chambers is controlled by adjusting the position of the rotary valve. In this way, the metering and distribution of fluids in the cartridge can be varied depending on the specific protocol, which allows sample preparation to be adaptable to different protocols such as may be associated with a particular sample type for different types of analysis or different types of samples. For example, the sample cartridge can include a means for cell lysis, e.g., a sonication means so that bacteria and cells in a fluid sample to be analyzed can be lysed. Additional lysis means suitable for use with the instant invention are well known to persons of skill in the art, and can include, chemical lysis, mechanical lysis, and thermal lysis. In some embodiments, the sample includes bacteria, eukaryotic cells, prokaryotic cells, parasites, or viral particles.
In some embodiments, the cartridge is configured to facilitates sample processing steps that are performed from initial sample preparation steps, intermediate processing steps, and further processing steps to facilitate a detection of a target analyte in the biological sample with an attached reaction vessel. For example, sample processing can include preliminary preparation steps, such as filtering, grinding, mincing, concentrating, trapping debris or purifying a rough sample, or steps for fragmenting of DNA or RNA of the target analyte, such as by sonication or other mechanical or chemical means. Sample processing can include various intermediate processing steps, such as filtering, chromatography, or further processing of nucleic acids in the sample, including but not limited to chromatography, bisulfite treatment, reverse transcription, amplification, hybridization, ligation, or fragmentation of DNA or RNA. Sample processing may further include final processing steps, such as final amplification, hybridization, sequencing, chromatographic analysis, filtering and mixing with reagents for a reaction to detect the target analyte, which detection can include optical, chemical and/or electrical detection. While the sample cartridge typically performs analytical testing in an attached reaction tube or reaction vessel, it is appreciated that the sample cartridge can utilize various other means as well, e.g. a semiconductor chip that can be incorporated into the reaction vessel that extends from the body of the cartridge.
In some embodiments, the sample processing device can be a fluid control and processing system for controlling fluid flow among a plurality of chambers within a cartridge, the cartridge comprising a housing including a valve body having a fluid sample processing region continuously coupled fluidically with a fluid displacement chamber. The fluid displacement chamber is depressurizable to draw fluid into the fluid displacement chamber and pressurizable to expel fluid from the fluid displacement chamber. The fluid sample processing region includes a plurality of fluid transfer ports each fluidically coupled with one of a plurality of external ports of the valve body. The fluid displacement chamber is fluidically coupled with at least one of the external ports. The valve body is adjustable with respect to the plurality of chambers within the housing to allow the external ports to be placed selectively in fluidic communication with the plurality of chambers. In some embodiments, the valve body is adjustable with respect to the housing having multiple chambers, to place one external port at a time in fluidic communication with one of the chambers.
In some embodiments of the cartridge, the fluid sample processing region can be disposed between the fluid displacement chamber and at least one fluid transfer port. The term “fluid processing region” refers to a region in which a fluid sample is subject to processing including, without limitation, chemical, optical, electrical, mechanical, thermal, or acoustical processing. For example, chemical processing may include a chemical treatment, a change in pH, or an enzymatic treatment; optical processing may include exposure to UV or IR light; electrical processing may include electroporation, electrophoresis, or isoelectric focusing; mechanical processing may include mixing, filtering, pressurization, grinding or cell disruption; thermal processing may include heating or cooling from ambient temperature; and acoustical processing may include the use of ultrasound (e.g. ultrasonic lysis). In some embodiments, the fluid processing region may include an active member, such as a filter, to facilitate processing of the fluid. In some embodiments, filtration or other active processing steps can occur in one of the cartridge chambers prior to the sample fluid entering the fluid sample processing region. Additional active members suitable for use with the instant invention are well known to persons of skill in the art. In some embodiments, an energy transmitting member is operatively coupled with the fluid sample processing region for transmitting energy thereto to process fluid contained therein. In some embodiments, the valve body includes a crossover channel, and the valve body is adjustable with respect to the plurality of chambers to place the crossover channel in fluidic communication with two of the chambers concurrently.
The cartridge housing includes one or more branches that extend to one or more transfer ports to which a reaction vessel can be attached so as to facilitate transfer of fluid sample from a chamber of the cartridge into the reaction vessel. In some embodiments, the reaction vessel extends from the housing of the cartridge. These aspects can be understood further by referring to U.S. Pat. No. 8,048,386. It is understood that fluid may flow in either direction into or out of the transfer ports in various embodiments fluid flow is not limited in any particular direction. For example, in an embodiment having a pair of transfer ports, air may be pumped into or evacuated from one of the pair of transfer ports to facilitate flow of the fluid sample into a conduit of the reaction vessel through the fluid transfer port.
In some embodiments, the sample cartridge is configured for processing an unprepared sample, which can include steps of: receiving a sample cartridge in a cartridge receiver of a module, the sample cartridge including a biological fluid sample to be analyzed, a plurality of processing chambers fluidically interconnected by a moveable valve body; receiving an electronic instruction to process the biological sample into a prepared sample from the module; performing a sample preparation method in the sample cartridge to process the biological fluid sample into the prepared sample; transporting the prepared sample into a reaction vessel fluidically coupled with the sample cartridge; and performing analysis of the biological fluid sample within the reaction vessel. In some embodiments, transporting the sample may include steps of: moving a cartridge interface unit to move the valve body to change fluidic interconnections between the plurality of sample processing chambers; applying pressure to a pressure interface unit to move fluid between the plurality of processing chambers according to position of the valve body; and fluidically moving the prepared sample into the reaction vessel. Performing analysis of the fluid sample within the reaction vessel with the module.
The present invention relates generally to a system, device and methods for fluid sample manipulation and analysis, in particular, sample cartridges that facilitate processing and analytical testing of biological samples.
In one aspect, the invention pertains to a sample cartridge of unitary design in which various components are integrally formed, and to various other improvements of the sample cartridge, valve assembly, lid sealing, and attached reaction vessel. The sample cartridge device can be any device configured to perform one or more process steps relating to preparation and/or analysis of a biological fluid sample according to any of the methods described herein. In some embodiments, the sample cartridge device is configured to perform at least sample preparation. The sample cartridge can further be configured to perform additional processes, such as detection of a target nucleic acid in a nucleic acid amplification test (NAAT), e.g., Polymerase Chain Reaction (PCR) assay, by use of a reaction tube attached to the sample cartridge. In some embodiments, the reaction tube extends from the body of the sample cartridge. Preparation of a fluid sample generally involves a series of processing steps, which can include chemical, electrical, mechanical, thermal, optical or acoustical processing steps according to a specific protocol. Such steps can be used to perform various sample preparation functions, such as cell capture, cell lysis, binding of analyte, and binding of unwanted material. A sample cartridge suitable for use with the invention, includes one or more transfer ports through which the prepared fluid sample can be transported into an attached reaction vessel for analysis. In some embodiments, the transfer ports and fluidic passages contain bubble traps to capture air and prevent it from entering the reaction vessel. In some embodiments the fluidic passages are designed to help remove air from the reaction tube as it is displaced with the processed fluid sample to be analyzed.
An exemplary use of a reaction vessel for analyzing a biological fluid sample is described in commonly assigned U.S. Pat. No. 6,818,185, entitled “Cartridge for Conducting a Chemical Reaction,” filed May 30, 2000, the entire contents of which are incorporated herein by reference for all purposes. Examples of a conventional sample cartridge and associated module are shown and described in U.S. Pat. No. 6,374,684, entitled “Fluid Control and Processing System” filed Aug. 25, 2000; U.S. Pat. No, 8,048,386, entitled “Fluid Processing and Control,” filed Feb. 25, 2002; and U.S. Provisional Application No. 63/217,672 filed Jul. 1, 2021 and entitled “Universal Assay Cartridge and Methods of Use”, the entire contents of which are incorporated herein by reference in their entirety for all purposes.
Various aspects of the sample cartridge 100 can be further understood by referring to U.S. Pat. No. 6,374,684, which describes certain aspects of a conventional sample cartridge and various components in greater detail. Such conventional sample cartridges can include a fluid control mechanism, such as a rotary fluid control valve, that is connected to the chambers of the sample cartridge. Rotation of the rotary fluid control valve permits fluidic communication between chambers and the valve so as to control flow of a biological fluid sample deposited in the cartridge into different chambers in which various reagents can be provided according to a particular protocol as needed to prepare the biological fluid sample for analysis. To operate the rotary valve, the cartridge processing module includes a motor such as a stepper motor that is typically coupled to a drive train that engages with a feature of the valve in the conventional sample cartridge to control movement of the valve in coordination with movement of the syringe, thereby resulting movement of the fluid sample according to the desired sample preparation protocol. The fluid metering and distribution function of the rotary valve according to a particular sample preparation protocol is demonstrated in U.S. Pat. No. 6,374,684. It is appreciated that the above noted aspects of the conventional sample cartridge and associated module can be utilized in the unitary cartridge design as well.
Details of the unitary cartridge design as well as various other improvements over the conventional sample cartridge can be further understood by referring to
In contrast to the above described features, conventional cartridges of similar design (such as that shown in
In regard to the first aspect, the unitary cartridge body is formed such that the separate syringe tube in the conventional design has been eliminated, and is integrally formed with the cartridge body. The syringe lumen can be reduced in diameter which allows an increase in the size of the multiple chambers surrounding the syringe tube. Forming the syringe lumen integrally with the cartridge body simplifies the manufacture and assembly of the cartridge.
In regard to the second aspect, the improved sample cartridge includes a gasket that is incorporated into the valve body. In some embodiments, the gasket is no longer flat, but is angled or curved to protrude upwards, which allows higher normal forces (i.e. normal to the gasket plane) to be generated within the gasket material to provide improved sealing and pressurization as compared to the conventional design having a flat gasket requiring substantially higher normal force to attain the same level of sealing and pressurization.
In regard to the third aspect, the cartridge body can be integrally formed with the cartridge base. In some embodiments, the cartridge base is configured so that the valve assembly is insertable from an underside thereof. In some embodiments, the cartridge base is configured with a negative conical valve surface with multiple openings corresponding to the multiple chambers to interface with a conical gasket of the valve assembly, the gasket having one or more holes for aligning with one or more selected openings of the interface upon rotation of the valve assembly. In some embodiments, the unitary cartridge body can be configured to receive the valve body from an underside thereof.
In regard to the fourth aspect, the cartridge can include a tube mount that is configured to receive and securely affix to a reaction vessel without requiring disassembly of the cartridge. In some embodiments, the reaction vessel flange is configured to releasably attach to a corresponding flange of the reaction vessel so that the reaction vessel can be removed, replaced or exchanged with a differing type of reaction vessel. This is advantageous as it allows specialized reaction vessels to be attached to the sample cartridges after initial assembly. In some embodiments, the reaction vessel flange of the cartridge body is a snap-fit design. In some embodiments, the tube mount is configured to securely affix the reaction vessel, after which it cannot be readily removed.
In regard to the fifth aspect, the sample cartridge can include valve body designs that are modified to control fluid flow of the biological sample. In some embodiments, the valve body includes a filter plane angled relative a horizontal plane so as to slow fluid flow of the biological sample as it flows toward the filter so as to more uniformly spread across the filter. In some embodiments, the valve assembly includes multiple support ribs that support the filter to ensure more uniform flow of the fluid sample through the filter. In some embodiments, the valve body includes multiple walls defining a filter chamber and a flowpath for the fluid flow that direct the fluid sample into the filter chamber. The filter chamber can be sealed by a membrane sealed over the multiple walls. It is appreciated that these modified valve designs can be used in a conventional valve assembly having a separate syringe tube attached thereto or a valve assembly configured for use with the unitary cartridge body described above.
In regard to the sixth aspect, the cartridge can include a thin film lid insert having one or more layers that facilitate sealing atop the cartridge, between the cartridge and lid. The thin film insert can include one or more layers to facilitate sealing of the multiple chambers after filling with reagents, yet still allow a user to input the fluid sample in the cartridge after sealing. The lid can include a thin film insert that is sealable by as heat sealing.
In contrast, a conventional sample cartridge is shown in FIGS. 2A2B, which is consistent with the standard GeneXpert sample cartridge currently on the market. In this design, the cartridge body is separately formed from the base and the syringe tube is a separate tube that is inserted into the cartridge body before the base is attached to the cartridge body. The bottom of the syringe tube is attached to the valve body, which is relatively flat and is sealed by a flat gasket on the bottom of the cartridge body. The PCR tube is slid into the cartridge flange during initial assembly and secured by an additional component and attachment of the cartridge base. Accordingly, once the PCR tube is attached during initial assembly, it cannot easily be removed without disassembling the entire cartridge. This problem can be overcome in an alternative embodiment where the cartridge is designed to allow post-assembly attachment of the reaction tube.. This is advantageous when attaching specialized reaction tubes, which may incorporate costly materials, componentry or devices. After all the cartridge components are assembled, which can include components with pre-supplied reagents and/or processing agents, the cartridge lid (not shown) is attached by ultrasonic welding. While effective in sealing a polymer lid to the polymer cartridge body, the ultrasonic vibrations can potentially compromise interfaces between other components and/or inadvertently loosen or release reagents or processing agents provided in the cartridge. Thus, the design approach of conventional cartridges has certain drawbacks and may inhibit the ability to modify and/or include additional features. Accordingly, the improved design features not only simplify and improve manufacturing, assembly and operation of the sample cartridge, but are amenable to including various other features with the sample cartridge (e.g. alternative reaction vessels, pre-supplied reagents in solid or liquid form, etc.).
Although these designs show valve bodies that are relatively flat and are attached to a separate syringe tube, it is appreciated that the improved valve body described previously can be designed to accommodate either approach (e.g. ultrasonic lysing, chemical lysing). For example, the valve body 20 in
In another aspect, the improved sample cartridge design could include variations of the tube mount on the unitary cartridge body described previously. The tube mount can be formed in the unitary body such that no other component other than the cartridge body and reaction vessel are needed to sealingly couple the reaction vessel to the sample cartridge. Such a design simplifies tooling, reduces plastic, reduces leak possibility, reduces the amount of material needed and can allow for faster molding cycling times, lower cost and maintenance.
In a conventional two-channel reaction vessel with two fluidic ports both fluidically coupled to the sample cartridge, the flow path of the reaction vessel forms a closed loop such that fluid flow within the reaction vessel is controlled by controlling pressure through both fluidic ports. In this alternative approach, the reaction vessel has a “no-loop” design where one channel (e.g. bottom channel) is fluidically coupled to the sample cartridge while the other channel (e.g. top channel) is closed to atmosphere. In some embodiments, the channel is open to atmosphere through a stop or fit, which is a hydrophobic element that passes air but not liquid, not having to route back through a crossover and thus simplifying the cartridge. Not only is this design simplified and require less material, but there are significant tooling advantages associated with this design. Additionally, this eliminates the possibility of improperly attaching the reaction vessel upside-down.
In still another alternative design, the “no-loop” tube can be dead-headed, with one channel being closed (rather than open to atmosphere) which basically pressurizes the dead head. In some embodiments, the system is designed so that the channel deadheads in the cartridge. In still other embodiments, the reaction vessel can be designed to avoid dead heading in the cartridge, but rather to dead head in the reaction vessel itself. This eliminates the need to seal one port, as well as the need for an upper port on the cartridge. One issue with a dead headed reaction tube is the pressure ratio between the empty tube (ET) (sum of the top channel, reaction chamber, bottom channel, bottom channel on cartridge to the sealing surface) and the filled tube (FT) (sum of reaction chamber, bottom channel, bottom channel on cartridge to the sealing surface), where pressure ratio would be ET/(ET-FT). This number ×1 Atmosphere (e.g. 15 PSI) is the pressure in the reaction tube chamber, which will be higher with higher volume reaction tubes. So, in such embodiments, if the pressure ratio were 10:1, then the tube pressure would be 10 atm or about 150 PSI. This approach assumes that sufficient pressure can be maintained in the reaction tubes and cartridges (e.g. about 150 PSI).
In cartridge designs that cannot maintain sufficient pressure, this drawback can be mitigated by pulling negative pressure on the reaction tube before filling. By this approach, in the case of a 10:1 pressure ratio, if a negative pressure at around 1/9 atmosphere was pulled, the end result would be around 15 PSI of tube pressure. Another challenge with this approach is that it may be more difficult to evacuate all of the fluid from the reaction chamber as pressures turn negative as the tube is emptied. However, by further increasing headspace volume (e.g. increasing chamber size or adding flowpath), pressure ratios can be reduced so that the fluid can be sufficiently evacuated in accordance with the desired workflow.
In one aspect, this “no-loop” tube approach can be readily implemented by minor modifications to existing tools used to from conventional reaction tubes and cartridges. As shown in
While the unitary cartridge design is shown and described above, it is appreciated that this same concept and operation can be performed on a conventional sample cartridge, such as that shown in
In another aspect, the unitary cartridge can utilize an improved approach to sealing a top lid component atop the cartridge. While this approach is described with respect to the unitary cartridge with integrated lid, it is appreciated that aspects of this film sealing approach can apply to separate lids on any cartridge, including the conventional cartridge in
In some embodiments the lid is integrally molded with the cartridge body and the lid is attached to the cartridge body by film sealing, rather than ultrasonic welding as used in conventional cartridge. The use of film sealing reduces damage to cartridge components and reducing costs, including possibly reducing the volume of plastic in the cartridge significantly. In this approach a thin-film insert is prepared to seal atop the cartridge between the lid and the cartridge. As shown in
In yet another aspect, the cartridge can include feature to provide for magnetic separation. The basic principle behind magnetic separation is that a magnetic particle is attached to a probe that will bind to a target specific to a molecule/target to isolate. This includes not only intact cells or organisms, but also DNA, RNA, and protein targets. This magnetic conjugate is then introduced to the sample pool containing the target. Generally, this is done in a liquid, where the kinetics are quite favorable. Once attached to the target, a magnet or magnetic field can be used to capture and hold the magnetically tagged target, and the non-target can be washed away, or undergo further steps if the purpose of the magnetic capture was to remove unwanted elements from the sample (depletion mode). If the molecule of interest is the magnetically tagged target, the magnetic capture can hold the target and endure rather robust rinsing/washing steps in addition to exposure to reagents and chemistry in situ. Then, (in most commercially available products) the target can be eluted by simply removing the magnet or magnetic field. There are also chemistry methods of de-coupling the ligand from the iron particle.
In the case of the magnetic separation in a sample cartridge, such as those described herein, the method of release will most likely be achieved by using the sonication horn to release the target. A ‘removal of the magnetic field’ proposal will be described as well. There are two basic release models, the “impact” model and the “bond-breaking” model.
In the impact model, the magnetic particle(s) are tied to a cell/bacteria/spore and then bound to the magnetic field. The actual target lies in the contents of the cell, and are accessed by using the ultrasonic horn to break the cell, releasing its contents.
In the bond-breaking model, the magnetic particles are tied to the target molecule(s) and bound to the magnetic field. The targets are released by mechanically breaking the ties to the magnetic particle using ultrasonic energy. There are also chemical methods known to persons of skill in the art that can do this.
It is appreciated that while these embodiments depict a valve assembly with a conventional syringe tube, these concepts can be incorporated into the improved valve assemblies described herein, including the unitary cartridge body.
In the embodiment of
In some embodiments, software commands to direct fluid manipulations to perform each of the above methods involving pumping the magnetic conjugate from one of the inner chambers into the sample chamber and gently agitating the solution can be included. This could also occur in a separate fresh chamber if the sample type requires it (e.g. post pre-filter). The mixture is then passed through the filter chamber, where the target is bound to the magnet directly (e.g. in the case of the first and second configuration) or to the filter surface adjacent the magnet (e.g. third configuration). Wash steps can then be performed, including reversing the flow off of the filter. Then to obtain the target, sonication is applied and an elution is performed.
In another aspect, the valve interface can include a magnetic capture chamber that would allow release of the magnetic field to provide the capability of more powerful sample preparations and purifications using magnetic separation. In some embodiments, a direct port channel on syringe tube is modified to create a magnetic capture chamber, as shown in
While these features are shown in regard to a valve body interface attached to a separate syringe tube it is appreciated that these concepts could readily be applied to the valve interface of the unitary cartridge body as described herein, for example, as shown in
While the above feature have been discussed as potential features of a sample cartridge, it is appreciated that a given sample cartridge could include any single feature or any combination of these features, as well as various other additional features discussed further below. There may be reason to include only certain combinations of features, which can include compatibility with existing modules, protocols or reaction vessels, minimizing changes in manufacturing or assembly workflow, availability of materials or manufacturing tools, or various other reasons. Further, given the breadth of modification and additional features, it may be advantageous to implement these features in design iterations to minimize the impact of changes in the manufacturing workflow as well as any compatibility issues with existing devices or methods, or simply to try differing approaches to gauge their success. The following table represents iterative designs having select features incorporated herein for at least some of the reasons discussed above. It is appreciated that various other designs could be realized departing from the matrix shown. Aspects of each feature are summarized/discussed further below.
With this arrangement, a highly simplified, typical software protocol for magnetic capture and purification can be realized. In one example, this simplified protocol can include the following steps: 1.) Aspirate buffer, direct path (“D”), dispense to waste to prime the valve-body and chambers, filter path (“F”). 2.) Aspirate from magnetic bead reagent chamber D, dispense to sample chamber, D. 3.) Toggle, D, sample chamber. 4.) Big Aspirate, D, Sample. 5.) Slow Dispense, D, to waste, the capture chamber is active on this step. 6.) Small Aspirate, D, from buffer (picking off mag beads because magnet is not in position). 7.) Fast Dispense, D, to target chamber. 8.) Repeat steps 4 through 7 until desired total amount of Sample is processed. 9.) Optional concentrator step, Large aspirate (all of) from target chamber, Slow dispense to waste, D. 10.) Aspirate from buffer or other reagent, D, Dispense optionally to PCR beads chamber. This step concentrates the target in buffer of choice and then sends to mix with PCR reagents, skipping the filter, if desired, or the mix could be sent to the filter, lysed and processed on the next step. In some embodiments, magnetic purification can operate independently of the filter if desired. Such protocols can be utilized in a variety of applications, including but not limited to: WBC depletion or enrichment for HIV quant assay; target enrichment for methylation, cancer assays (plasma pool); bacteria isolation for sepsis; and protein purifications
In one aspect, the cartridge design is configured to be compatible with conventional valve bodies and/or compatible with conventional reaction vessel (i.e. reaction tube). It is advantageous for the first design iteration, Design 1.0, to be compatible with the other current production components, which includes the lid, reaction tube and valve body assembly. The cartridge ‘foot’ or base is compatible in the sense that it is integrated, so no longer is needed as a separate component.
In another aspect, the cartridge can be configured with gasket-less tube ports (i.e. fluid ports to the reaction vessel). In the current conventional cartridge design, the cartridge body is overmolded with a suitable material (e.g. TPV (Thermo Plastic Vulcanate)) that provides an elastic sealing interface for both the valve body sealing surface and the reaction tube ports. Eliminating the elastic from the tube port sealing surface simplifies the cartridge body molding tool, and greatly simplifies the overmolding tool by eliminating the requirement for side action in the overmolding tool.
In yet another aspect, the cartridge design can be configured with a snap-in tube. The current conventional cartridge design requires both the valve body and the reaction tube to be placed on the cartridge body, and then the separate foot component is installed to retain both the reaction tube and the valve body. By designing the tube retention feature so that the reaction tube can be snapped in (e.g. by a snap-fit tube mount), the constraint in the order of assembly in the manufacturing line is removed. Removing this constraint allows for more manufacturing flexibility and ultimately will result in lower logistics costs and improve assembly design. Additionally, in the case of high value reaction tube designs, including next generation reaction vessel having diagnostic chips and/or on-board microarrays, the value of the reaction tube component can sometimes exceed the value of the assembled cartridge component. By allowing a different order of assembly, the aggregate component risk can be reduced, so that only tested good cartridge assemblies can be mated with tested good reaction tube assemblies, reducing sunken-cost impacts due to defects.
In another aspect, the cartridge design can be configured with a snap-in valve body. The conventional cartridge design can utilize a valve assembly mounted to the separate syringe tube and requires assembly before attaching the separate cartridge base. In the unitary cartridge design, the combination of a snap-in tube design and snap-in valve design removes the need for a separate foot component, saving component and logistics and assembly costs. The valve assembly can be inserted from an underside of the integrally formed base and snapped into plate (e.g. by a snap-fit coupling). Additionally, a key benefit of the snap in valve body design is that the elimination of the separate foot component eliminates two mechanical tolerance stacks from the valve body assembly tolerance equation. This is the snap to valve face tolerance on the foot, and the snap window to gasket surface on the cartridge body. This can be advantageous, because with a relatively thin (e.g. 8 mm) total seal thickness and desired compression specification range (e.g. 0.2-0.4 mm), the stacked tolerances can eliminate the actual process window for an acceptable final assembly. Typically, the molded in snap produces only one dimension of interest, which is the top of the rubber seal to the lip of the snap. The design is devised so that the distance from the top surface of the snap feature to the snap lip is held constant being in the same piece of steel, therefore making the measurement of the gasket top to the snap lip greatly simplified. Accordingly, in-process controls can be implemented to hold a tight range on this dimension. This translates overall to much higher acceptable final assembly yield as well as a reduced or eliminated exclusion matrix, greatly reducing production yield losses and the costs associated with them.
In another aspect, the cartridge design can include a valve body snap-in feature. In some embodiments, this snap-in feature can be made using a 6-blade collapsing core. This feature is included in Designs 1 and 1.5 This feature can utilize an ‘annular snap design’ 29′, as shown in
In still another aspect, the cartridge design can include a unitary cartridge body having an integrated ‘foot’ or base. This feature is shown in
In another aspect, a semi-annular valve body snap feature can be used, as shown in
In yet another aspect, the cartridge can include a reaction vessel snap-in mount that is formed by an A side motion, as shown in
In still another aspect, the cartridge can include a tube snap-in feature formed by a collapsing core.
Another design feature is the front face of the cartridge body being formed by a tool having a slide and collapsing fingers.
Another aspect, described previously, is the integrated syringe bore, which obviates the need for a separate syringe tube inserted through a syringe barrel. A cross-sectional side view of this feature is shown in
Another feature, described previously, is the conical valve assembly, as shown in
In one aspect, the overmolding of seals/gaskets is simplified by use of this valve assembly. The valve is also designed so that the rubber overmolding process is removed from the cartridge body and moved to the much easier to handle valve body, which results in significantly improved cycle times. The rubber of the gasket is then also used to provide a sealing ring for the filter cavity. In another aspect, the valve assembly can use a snap-on cap. In this embodiment, the valve is design with undercut features in the drive flange, allowing the use of a snap in valve body cap. The undercuts of the snap-in coupling features can be made simply by using lifters instead of ejectors and provides for a simple tool design with great benefits. Additionally, this design no longer requires an ultrasonic welding process requires to close the valve body. The design further allows for different thicknesses of filter materials without changing the process. Accordingly, the filter materials within the valve assembly are no longer subjected to ultrasonic forces during the assembly process, which is the most significant issue in the improved filter designs of next generation cartridges. The design will allow for the cap material to be different than the valve material, which is advantageous in allowing more versatility to use other components or conventional components (e.g. syringe tube) and eliminate the need for specialized grease. In some embodiments, the cap can be formed from a liquid silicone resin, which does not have a compression set. Additionally, the substituted material for the valve body will be cheaper than the currently used polycarbonate, and more chemical resistant.
The ultrasonic welding stresses locked into the current polycarbonate valve body assembly design will no longer exist, so the chemical compatibility of the component should be dramatically improved. In one aspect, the order of assembly is now no longer process constrained so that in some embodiments (e.g. Design 2.0), the valve body can be assembled at any point in the process. This includes the valve cap and filter material, which can be assembled at any point in the process
The current conventional cartridge body is gated near the top of the cartridge body. Because Design 1.0 is based on conventional tooling techniques, it is also gated in this area.
Because Design 1.0 is based on conventional tooling techniques, it is also gated in this area. Designs 1.5 and 2.0 utilize gating near the bottom of the cartridge. This feature is driven by the fact that the foot is now integrated into the design and there is more opportunity to inject the plastic in this area and may be more beneficial from a mold flow and tool simplicity point of view.
Another feature of the sample cartridge is an integrated lid.
In the foregoing specification, the invention is described with reference to specific embodiments thereof, but those skilled in the art will recognize that the invention is not limited thereto. Various features, embodiments and aspects of the above-described invention can be used individually or jointly. Further, the invention can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive. It will be recognized that the terms “comprising,” “including,” and “having,” as used herein, are specifically intended to be read as open-ended terms of art. Any references to publication, patents, or patent applications are incorporated herein by reference in their entirety for all purposes.
This application is a Non-Provisional of and claims the benefit of priority of U.S. Provisional Application No. 63/319,993 filed Mar. 15, 2022, the entire contents of which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63319993 | Mar 2022 | US |
