Tube assembly for use in processing a sample

Abstract

A tube assembly for processing a sample, comprising a container portion comprising a reservoir for holding a sample and processing reagents therein, and a cap comprising a sealing element, the container portion comprises a vent and the cap is operable from an upper position and a lower, sealed position in which the sealing element extends into the container portion beyond the vent and contacts the inner surface of the container portion and seals the reservoir.

Description

[0001] TUBE ASSEMBLY FOR USE IN PROCESSING A SAMPLE

[0002] The present invention relates to a tube assembly for use in processing a sample.

[0003] In particular, the invention relates to a tube assembly for use in processing a sample, the processing including nucleic acid amplification such as polymerase chain reaction (PCR) testing. Nucleic acid amplification reactions such as the polymerase chain reaction (PCR) provide a means for detecting target nucleic acid specifically and with high sensitivity, and are used to diagnose certain infectious diseases and genetic changes. Typically, PCR reactions are carried out in polypropylene tubes comprising a conical bottom, and a push-fit cap. Tight sealing of the cap is important to help minimise cross-contamination between samples, and to prevent significant volume losses through evaporation during the PCR reaction.

[0004] A disadvantage of conventional PCR tubes is that as the cap is push-fit onto the polypropylene tube, pressure inside the polypropylene tube increases due to compression of the gas, such as air, inside the polypropylene tube. This may provide resistance against sealing the polypropylene tube. In particular, it would be beneficial to provide automated sample processing apparatus to handle such PCR tubes. In such automated sample processing, the cap may need to be removed to introduce samples into the tube, and subsequently refitted. During the automated refitting of the cap to the tube, the cap may need to be inserted a greater distance into the tube when compared to a conventional PCR tube and cap. This greater distance may therefore result in a greater pressure build-up in the tube compared to a conventional PCR tube and cap. The resistance against sealing the polypropylene tube encountered by such an automated sample processing apparatus may present a challenge to reliably seal each polypropylene tube.

[0005] Furthermore, conventional PCR tubes have the risk of the cap being unintentionally removed from the polypropylene tube, for example, due to excess pressure build-up in the polypropylene tube. This may allow for undesired cross-contamination between samples, and allow significant volume losses through evaporation during the PCR reaction. This is particularly significant again when an automated sample processing apparatus handles such PCR tubes, and avoiding such unintentional removal of the cap would allow for more efficient processing of the samples and reduces the need for user intervention to manually replace the cap back into the polypropylene tube for example. Ensuring a user cannot manually remove the cap after a sample is processed is also desirable.

[0006] It would therefore be beneficial to provide a tube assembly which overcomes the above disadvantages.

[0007] According to a first aspect of the present disclosure, there is provided a tube assembly for processing a sample, the tube assembly comprising: a container portion comprising a reservoir forholding a sample and processing reagents therein, and a cap engaging with the container portion, the cap comprising a sealing element, wherein the container portion comprises a vent defined in an inner surface of the container portion, and wherein the cap is operable from an upper position in which the sealing element contacts the inner surface of the container portion and the vent defines an air venting passage from within the reservoir to outside the reservoir, to a lower, sealed position in which the sealing element extends into the container portion beyond the vent and contacts the inner surface of the container portion and seals the reservoir, such that gas within the reservoir is vented through the air venting passage as the cap is transitioned from the upper position to the lower, sealed position.

[0008] Advantageously, as the gas, such as air, within the reservoir is vented from within the reservoir, this prevents the build-up of excess pressure in the reservoir as the cap is transitioned from the upper position to the lower, sealed position. As a result, the resistance against sealing the reservoir is lower, and the reservoir is more reliably sealed. This is particularly advantageous when the tube assembly is used in an automated sample processing apparatus.

[0009] Optionally, the container portion comprises at least one latch configured to secure the cap in the lower, sealed position. Optionally, the at least one latch is configured to contact an upper surface of the cap in the lower, sealed position. Advantageously, the at least one latch reduces the risk of the cap being unintentionally transitioned back from the lower, sealed position to the upper position for example, due to excess pressure build-up in the reservoir.

[0010] Optionally, the at least one latch is configured to contact a side surface of the cap in the upper position. The at least one latch may therefore provide a guiding surface along which the side surface of the cap may slide as the cap is transitioned from the upper position to the lower, sealed position. This may assist in keeping the cap in a vertical orientation relative to the container portion, ensuring a good seal when the cap is in the lower, sealed position.

[0011] Optionally, the at least one latch comprises at least one protrusion. Optionally, the at least one protrusion is arranged on at least one resilient beam, and wherein the cap comprises a shoulder portion configured to contact the protrusion and reversibly deform the at least one resilient beam as the cap is transitioned from the upper position to the lower, sealed position. Advantageously, this arrangement minimises the number of moving parts of the tube assembly, and provides a reliable latch.

[0012] Optionally, the at least one protrusion is integrally formed with the at least one resilient beam. Optionally, the at least one resilient beam is integrally formed with an upper portion of the container portion. Advantageously, this may allow for ease of manufacture of the container portion, for example by injection moulding, without the need to attach a separate latch component.Optionally, the sealing element comprises at least one sealing rib. Advantageously, the at least one sealing rib provides reliable sealing contact between the sealing element and the inner surface of the container portion to seal the reservoir when the cap is in in the lower, sealed position.

[0013] Optionally, the sealing element comprises an upper sealing rib and a lower sealing rib, the upper sealing rib spaced from the lower sealing rib in a longitudinal direction. In the upper position the lower sealing rib may hold the cap within the container portion. For example, by a friction fit between the lower sealing rib and the inner surface of the container portion. The lower sealing rib may contact the inner surface of the container portion, such that the vent defines an air venting passage from within the reservoir to outside the reservoir past the lower sealing rib. Therefore, the lower sealing rib may not provide a perfect seal.

[0014] In the lower, sealed position the lower sealing rib may contact the inner surface of the container portion to seal the reservoir. In the lower, sealed position the upper sealing rib may also contact the inner surface of the container portion to provide a backup seal for the reservoir. The upper sealing rib may also assist in ensuring the cap is in a vertical orientation with respect to the container portion. Optionally, the vent comprises at least one groove defined in an inner surface of the container portion. Advantageously, a groove defined in an inner surface of the container portion ensures reliable venting of pressure from the reservoir, whilst allowing for a straightforward geometry to manufacture using, for example, injection moulding.

[0015] Optionally, in the upper position the sealing element contacts a circumference of the inner surface of the container portion, except at a portion of the inner surface which defines the vent.

[0016] Optionally, in the upper position the sealing element contacts at least 90% of the circumference of the inner surface of the container portion. For example, in the upper position the sealing element may contact at least 93% of the circumference of the inner surface of the container portion. For example, in the upper position the sealing element may contact between 90% and 99% of the circumference of the inner surface of the container portion. For example, in the upper position the sealing element may contact between 94% and 98% of the circumference of the inner surface of the container portion. For example, in the upper position the sealing element may contact 96% of the circumference of the inner surface of the container portion. In such examples, the at least one groove may be defined in less than or equal to 10% of the circumference of the inner surface of the container portion. For example, the at least one groove may be defined in between 10% and 1 % of the circumference of the inner surface of the container portion. For example, the at least one groove may be defined in between 6% and 2% of the circumference of the inner surface of the container portion. For example, the at least one groove may be defined in 4% of the circumference of the inner surface of the container portion. Advantageously, such arrangements minimise ingress of foreign matter into the reservoir, even when the cap is in the upper position. This may therefore reduce contamination of the reservoir even when the cap is in the upper position.According to a second aspect of the present disclosure, there is provided a packaged tube assembly. The packaged tube assembly may comprise the tube assembly according to the first aspect, or the third aspect as outlined below. The tube assembly may be contained within a sealed package, such as a sealed bag. The tube assembly may be shipped in a sealed package, such as a sealed bag. The sealed bag may be a sealed foil bag. The sealed package may be sterilised. Once the sealed package is opened by a user, the relatively small area of the vent does not allow enough transfer of moist air from outside the reservoir to inside the reservoir to compromise the contents of the reservoir in the time taken to prepare the tube assembly for a test and fully seal the reservoir.

[0017] The tube assembly may comprise a reagent in the reservoir. The reagent may be a lyophilised reagent. The lyophilised reagent may be in the form of a ball. The lyophilised reagent may comprise a mixture of primers, probes, enzymes, salts and other cofactors suitable for use in a PCR test. The lyophilised reagent may be configured to be rehydrated with purified nucleic acids before the PCR test is conducted. Said purified nucleic acids may be in suspension in an elution buffer. The sealed package may comprise a desiccant. Advantageously, the desiccant may maintain the integrity of a reagent in the tube assembly when the tube assembly is shipped with the reagent. The desiccant may comprise Zeolite (AhOsSi). The desiccant may be a Wisemini® Tyvek Molecular Sieve Desiccant Sachet provided by Wisesorbent® Technology LLC.

[0018] Optionally, the container portion comprises a reservoir sidewall defining the reservoir, and the reservoir sidewall comprises a transparent or translucent material. Advantageously, this may allow for the tube assembly to be used in real-time PCR, wherein a change in a fluorescence over the course of the reaction is measured by an instrument that detects fluorescence from inside the reservoir.

[0019] Optionally, the upper portion of the container portion is opaque. Optionally, the upper portion of the container portion is coloured black. Advantageously, when the tube assembly is inserted into realtime PCR testing apparatus, any ambient light is screened from entering the reservoir through the upper portion of the container portion and interfering with the light readings. Optionally, in the lower, sealed position the sealing element contacts the entirety of the circumference of the inner surface of the container portion. Optionally, in the lower, sealed position the sealing element contacts the entirety of the circumference of an inner surface of the reservoir sidewall. This may therefore act to seal the reservoir when the cap is in the lower, sealed position.

[0020] Optionally, the reservoir sidewall is separable from an upper portion of the container portion. Optionally, the reservoir sidewall comprises a different material to the upper portion. Advantageously, this provides a degree of modularity to the tube assembly, allowing for different upper portions to be coupled to different reservoir sidewalls during manufacturing.The upper portion of the container portion may be moulded separately to the reservoir sidewall. The upper portion of the container portion may be subsequently laser welded to the reservoir sidewall. The upper portion of the container portion may be moulded with the reservoir sidewall, together by a two-shot injection moulding process.

[0021] Optionally, the cap is configured to be completely separable from the container portion. Advantageously, this may allow for the cap to be replaceable, if faulty for example, and allow for the cap to manufactured separate to the container portion, before assembly prior to use.

[0022] Optionally, the cap comprises a central cap cavity defined by a cap sidewall. Advantageously, the central cap cavity may be used for removably engaging an adapter of a transport apparatus to move the tube assembly to different locations during processing by an automated sample processing apparatus.

[0023] Optionally, the central cap cavity is accessible through an aperture defined in an upper surface of the cap. Advantageously, this may permit said adapter of a transport apparatus to be inserted into the central cap cavity from above when the tube assembly is in an upright orientation during processing by an automated sample processing apparatus.

[0024] According to a third aspect of the present disclosure, there is provided a tube assembly for processing a sample, the tube assembly comprising: a container portion comprising a reservoir for holding a sample and processing reagents therein, and a cap engaging with the container portion, the cap comprising a sealing element, wherein the cap is operable from an upper position in which the reservoir is unsealed, to a lower, sealed position in which the reservoir is sealed, and wherein the container portion comprises at least one latch configured to secure the cap in the lower, sealed position.

[0025] The tube assembly according to the third aspect may comprise any features described herein with respect to the tube assembly according to the first aspect and the packaged tube assembly according to the second aspect.

[0026] An embodiment of the invention will be described, by way of example only, in the following Figures in which:

[0027] Figure 1 shows a perspective view of a tube assembly according to the present disclosure, with the cap in the upper position;

[0028] Figure 2 shows a cross-sectional perspective view of the tube assembly shown in Figure 1 ;

[0029] Figure 3 shows a further cross-sectional perspective view of the tube assembly shown in Figure 1 , with the cap in the lower, sealed position;

[0030] Figure 4 shows a cross-sectional front view of a portion of the tube assembly shown in Figure 1 , with the cap in the upper position; andFigure 5 shows a cross-sectional top view of the container portion of the tube assembly shown in Figure 1 through section A-A.

[0031] Figure 6A shows a plurality of components including a plurality of tube assemblies according to the present disclosure prior to packaging.

[0032] Figure 6B shows the packaged plurality of components including the plurality of tube assemblies. Figure 1 shows a perspective view of a tube assembly 100 according to the present disclosure. Figure 2 shows a cross-sectional perspective view of the tube assembly 100 shown in Figure 1. The tube assembly 100 comprises a container portion 10, and a cap 50. The tube assembly 100 is configured for use with a nucleic acid amplification reaction. Any suitable method of nucleic acid amplification reaction may be used with the tube assembly 100 according to the present disclosure. However, it is particularly envisaged that real-time (rt) polymerase chain reaction (PCR) nucleic acid amplification is used with the tube assembly 100 according to the present disclosure. Suitable methods of real-time PCR nucleic acid amplification are known to the skilled person. A review of real-time PCR is provided in Real-Time PCR Handbook, Life Technologies (URL: https: / / www.gene-quantification.de / real-time-pcr-handbook-life-technologies-update-flr.pdf), Withrow and MacEwen's Small Animal Clinical Oncology (Fifth Edition), 2013, page 131-142, and in Mackay etal, Nucleic Acids Research, vol 30(6): 1292-1305 (2002).

[0033] Nucleic acid amplification reactions such as real-time PCR offer a straightforward means for detecting target nucleic acid specifically and with high sensitivity. Real-time PCR provides the ability to monitor the progress of the PCR reaction as it occurs in real time. In particular, real-time PCR provides the ability to measure the amount of amplicon at each cycle which allows highly accurate quantification of the amount of starting material in samples.

[0034] The container portion 10 comprises a reservoir sidewall 30 defining a reservoir 32. The reservoir 32 is configured to hold reagents for said processing of samples. For example, the reservoir 32 is configured to hold reagents for PCR testing of samples. The reservoir 32 is also configured to hold a sample for processing.

[0035] Furthermore, real-time PCR provides the ability for amplification and detection to occur in a single tube, wherein the change in the fluorescence over the course of the reaction is measured by an instrument that combines thermal cycling with fluorescence detection and measurement. Detection of PCR products using real-time PCR instruments is widely known. Particularly, probe-based quantitative detection is widely used as it provides an accurate and reproducible analysis. Probebased analysis offers the least background fluorescence as compared to dye-based chemistries. The reservoir sidewall 30 therefore comprises a transparent or translucent material such as polypropylene. A transparent or translucent material allows for the tube assembly 100 to be used for processing of samples incorporating fluorescence detection.The container portion 10 further comprises an upper portion 20 coupled to the reservoir portion 30. The upper portion 20 comprises a material such as polypropylene. The upper portion 20 comprises a container sidewall 28. The container sidewall 28 and reservoir sidewall 30 together define an inner surface of the container portion 10, and a container cavity for receiving the cap 50 therein. The container portion 10 further comprises a pair of latches. Each latch comprises a resilient beam 22 coupled to the container sidewall 28 and extending upwards from the container sidewall 28. The resilient beams 22 are integrally formed with the container sidewall 28. The resilient beams 22 are positioned diametrically opposite one another, on opposite sides of the container sidewall 28. At the end of each resilient beam 22 is arranged a pair of inwardly facing protrusions 24. Each protrusion 24 is integrally formed with the corresponding resilient beam 22, and comprises a radiused upper edge.

[0036] Also at the end of each resilient beam 22 is arranged a pair of inwardly facing stopping protrusions 25. Each stopping protrusion 25 is integrally formed with the corresponding resilient beam 22, and comprises a flat upper edge.

[0037] The cap 50 is received within the container cavity defined in the container portion 10, and is configured to be fully removable from the container portion 10. The cap 50 comprises a cap sidewall 52 defining a central cap cavity 58 within the cap 50. The central cap cavity 58 is exposed to the outside of the cap 50 through an aperture 56 defined in the upper surface of the cap 50. The central cap cavity 58 may be used for removably engaging an adapter of a transport apparatus to move the tube assembly to different locations during processing by an automated sample processing apparatus. For example, a portion of said adapter may be inserted into the central cap cavity 58 from above when the tube assembly 100 is in the upright orientation illustrated in Figures 1 to 4.

[0038] The cap 50 further comprises a shoulder 54, the shoulder extending radially outwards from the cap sidewall 52.

[0039] The cap 50 further comprises a sealing element 60. A retaining means 62 is coupled to and integrally formed with the cap sidewall 52. The sealing element 60 surrounds the retaining means 62, such that the sealing element 60 is secured in place with respect to the rest of the cap 50. The sealing means 60 is formed from Santoprene®, a thermoplastic elastomer, or any other suitable compliant material, and comprises a pair of circumferential ribs 66, 68 extending radially from the main body of the sealing element 60. The circumferential ribs 66, 68 are spaced along the main body of the sealing element 60 in a longitudinal direction. In Figures 1 to 4, the longitudinal direction is illustrated in a vertical direction, from the top of the page to the bottom of the page. The sealing element 60, and the circumferential ribs 66, 68 are all substantially circular in cross-section perpendicular to the longitudinal direction.The container portion 10 further comprises a groove 64 defined in the inner surface. In particular, the groove 64 is defined in the container sidewall 28. The groove 64 is illustrated in Figure 4. Figure 5 illustrates a cross-sectional top view of the container portion 10 through section A-A of Figure 4, which shows the groove 64 defined in the container sidewall 28.

[0040] The cap 50 is illustrated in Figure 1 and 2 in an upper position, also referred to as partially sealed, an unsealed position or a shipping position. The tube is shipped to a user with the cap 50 in the upper position. Figure 4 also illustrates a portion of the tube assembly 100 when the cap 50 is in the upper position.

[0041] When the cap 50 is in the upper position, a lower surface of the shoulder 54 contacts an upper surface of each of the protrusions 24. This retains the cap 50 in the upper position in the absence of a threshold compressive force applied to the top of the cap 50. In the upper position, the protrusions 24 also contact the cap sidewall 52.

[0042] In the upper position, the upper rib 66 of the sealing element 60 does not contact the inner surface of the container portion 10. In contrast, in the upper position the lower rib 68 of the sealing element 60 does contact the inner surface of the container portion 10. In particular, the lower rib 68 of the sealing element 60 contacts the inner surface of the container sidewall 28 at a longitudinal location where the groove 64 is defined in the inner surface of container sidewall 28. The lower rib 68 of the sealing element 60 contacts a portion, but not all, of the inner surface of container sidewall 28. This is because the lower rib 68 does not extend fully into the groove 64. As a result, the reservoir 30 is not completely sealed by the lower rib 68 when the cap 50 is in the upper position, and the groove defines a vent. When the cap 50 is in the upper position, an air venting passage is defined from the reservoir 30, through the groove 64 and past the lower rib 68 of the sealing means 60, to the outside of the reservoir 30 and the tube assembly 100. This is because the cap sidewall 52 does not form an airtight seal with the rest of the container sidewall 28.

[0043] Contact between the lower sealing rib 68 and the inner surface of the container sidewall 28 provides sufficient frictional force to hold the cap 50 securely during shipping and initial automated handling.

[0044] The tube assembly 100 may be transported and supplied with the cap 50 in the upper position. Advantageously, whilst the cap 50 in the upper position does not completely seal the reservoir 30, the reservoir 30 is partially sealed, leaving only a small air venting passage. For example, the tube assembly 100 may be shipped in a sealed bag. Once the sealed bag is opened by a user, the relatively small area of the groove 64 does not allow enough transfer of moist air from outside the reservoir 30 to inside the reservoir 30 to compromise the contents of the reservoir 30 in the time taken to prepare the tube assembly 100 for a test and fully seal the reservoir 30. This acts to reduce the risk of contamination of the reservoir 30 during transportation and prior to use of the tube assembly 100.The tube assembly 100 may also be transported comprising a lyophilised reagent 91 in the form of a ball located within the reservoir 32. The lyophilised reagent 91 comprises a mixture of primers, probes, enzymes, salts and other cofactors suitable for use in a PCR test.

[0045] In use, an automated machine, may remove the cap 50 completely from the container portion 10. The automated machine may then add to the reservoir 30 a sample, and optionally further reagents, for processing of said sample, before returning the cap 50 to the container portion 10 in the upper position. In particular, the automated machine is configured to add to the reservoir 30 purified nucleic acids to rehydrate the lyophilised reagent before the PCR test is conducted. Said purified nucleic acids may be in suspension in an elution buffer.

[0046] It may be desired during processing of said sample to seal the reservoir 30. In particular, an airtight seal may be desired. To seal the tube assembly, a force is applied in the longitudinal direction to the top surface of the cap 50 when the cap 50 is in the upper position.

[0047] As each protrusion 24 comprises a radiused upper edge, when the force is applied in the longitudinal direction to the top surface of the cap 50, the lower surface of the shoulder 54 applies an outward radial force to each of the protrusions 24. This outward force causes the resilient beams 22 to bend outwardly, allowing the shoulder 50 to move past the protrusions 24 and the cap 50 to move further into the container portion 10 into a lower, sealed position.

[0048] In the lower, sealed position, the lower surface of the shoulder 54 contacts an upper surface of each of the stopping protrusions 25. This prevents further movement of the cap 50 into the container portion 10 than is necessary to seal the reservoir 30.

[0049] As the cap 50 moves further into the container portion 10 into a lower, sealed position, a gas pressure increases within the reservoir 30. However, due to the groove 64 defining an air venting passage, gas, such as air, from inside the reservoir 30 is vented out through the air venting passage during transition of the cap 50 from the upper to the lower, sealed position. This venting prevents a buildup of excess pressure within the reservoir 30, which would otherwise exert an upward force on the sealing element 60, requiring more force to be exerted on the cap 50. Therefore, the vent in the form of the groove 64 reduces the force required to seal the cap 50 in the container portion 10.

[0050] The lower, sealed position, also referred to as a sealed position, of the cap 50 in the container portion 10 is illustrated in Figure 3.

[0051] Once the shoulder 50 has moved past the protrusions 24 and the cap 50 has moved further into the container portion 10, the resilient beams 22 return to a vertical position, and the protrusions 24 act to lock the cap in a lower, sealed position. In particular, a lower surface of the protrusions 24 contacts an upper surface of the cap 50.In the lower, sealed position, the upper rib 66 of the sealing element 60 contacts the inner surface of the container portion 10. In particular, the upper rib 66 of the sealing element 60 contacts the inner surface of container sidewall 28 at the longitudinal location where the groove 64 is defined in the inner surface of container sidewall 28. The upper rib 66 of the sealing element 60 therefore contacts a portion, but not all, of the inner surface of container sidewall 28. This is because the upper rib 66 does not extend fully into the groove 64. In contrast, the lower rib 68 of the sealing element 60 contacts the entirety of the circumference of the inner surface of the reservoir sidewall 30. As a result, the reservoir 30 is completely sealed by the lower rib 68 when the cap 50 is in the lower, sealed position. In the present embodiment, the seal formed is an airtight seal.

[0052] Figure 6A shows a plurality of components including a plurality of tube assemblies 100 according to the present disclosure prior to packaging. The plurality of components includes three tube assemblies 100. A lyophilised reagent 91 in the form of a ball is located within the reservoir 32 of each tube assembly 100 prior to and during shipping. The plurality of components includes a desiccant 92 . The desiccant 92 maintains the integrity of the lyophilised reagent 91 during shipping and prior to use of the tube assembly 100. The plurality of components further includes a tray 93 to hold up to three tube assemblies 100. The plurality of components further includes a further cartridge component 94 which may be used during further steps in a PCR test.

[0053] Figure 6B shows the packaged plurality of components 1000 including the plurality of tube assemblies 100. The packaged plurality of components 1000 comprises the plurality of components in a sealed package 90. The sealed package 90 is a sealed foil bag, which is sterilised before the tube assemblies 100 are packaged within the sealed package 90.

Claims

Claims1. A tube assembly (100) for processing a sample, the tube assembly (100) comprising: a container portion (10) comprising a reservoir (32) for holding a sample and processing reagents therein, anda cap (50) engaging with the container portion (10), the cap (50) comprising a sealing element (60),wherein the container portion (10) comprises a vent (64) defined in an inner surface of the container portion (10), andwherein the cap (50) is operable from an upper position in which the sealing element (60) contacts the inner surface of the container portion (10) and the vent (64) defines an air venting passage from within the reservoir (32) to outside the reservoir (32), to a lower, sealed position in which the sealing element (60) extends into the container portion (10) beyond the vent (64) and contacts the inner surface of the container portion (10) and seals the reservoir (32), such that gas within the reservoir (32) is vented through the air venting passage as the cap (50) is transitioned from the upper position to the lower, sealed position.

2. A tube assembly (100) according to claim 1 , wherein the container portion (10) comprises at least one latch configured to secure the cap (50) in the lower, sealed position.

3. A tube assembly (100) according to claim 2, wherein the at least one latch is configured to contact an upper surface of the cap (50) in the lower, sealed position.

4. A tube assembly (100) according to claim 2 or 3, wherein the at least one latch is configured to contact a side surface of the cap (50) in the upper position.

5. A tube assembly (100) according to any one of claims 2 to 4, wherein the at least one latch comprises at least one protrusion (24).

6. A tube assembly (100) according to claim 5, wherein the at least one protrusion (24) is arranged on at least one resilient beam (22), and wherein the cap (50) comprises a shoulder portion (54) configured to contact the protrusion (24) and reversibly deform the at least one resilient beam (22) as the cap (50) is transitioned from the upper position to the lower, sealed position.

7. A tube assembly (100) according to claim 6, wherein the at least one protrusion (24) is integrally formed with the at least one resilient beam (22).

8. A tube assembly (100) according to claim 6 or 7, wherein the at least one resilient beam (22) is integrally formed with an upper portion (20) of the container portion (10).

9. A tube assembly (100) according to any preceding claim, wherein the sealing element (60) comprises at least one sealing rib (66, 68).

10. A tube assembly (100) according to claim 9, wherein the sealing element (60) comprises an upper sealing rib (66) and a lower sealing rib (68), the upper sealing rib (66) spaced from the lower sealing rib in a longitudinal direction.

11. A tube assembly (100) according to any preceding claim, wherein the vent (64) comprises at least one groove defined in an inner surface of the container portion (10).

12. A tube assembly (100) according to any preceding claim, wherein in the upper position the sealing element (60) contacts a circumference of the inner surface of the container portion (10), except at a portion of the inner surface which defines the vent (64).

13. A tube assembly (100) according to claim 12, wherein in the upper position the sealing element (60) contacts at least 90% of the circumference of the inner surface of the container portion (10).

14. A tube assembly (100) according to any preceding claim, wherein in the lower, sealed position the sealing element (60) contacts the entirety of the circumference of the inner surface of the container portion (10).

15. A tube assembly (100) according to any preceding claim, wherein the container portion (10) comprises a reservoir sidewall (30) defining the reservoir (32), and wherein the reservoir sidewall (30) comprises a transparent or translucent material.

16. A tube assembly (100) according to claim 14, wherein the reservoir sidewall (30) is separable from an upper portion (20) of the container portion (10).

17. A tube assembly (100) according to claim 14 or 15, wherein the reservoir sidewall (30) comprises a different material to the upper portion (20).

18. A tube assembly (100) according to any one of claims 14 to 16, wherein in the lower, sealed position the sealing element (60) contacts the entirety of the circumference of an inner surface of the reservoir sidewall (30).

19. A tube assembly (100) according to any preceding claim, wherein the cap (50) is configured to be completely separable from the container portion (10).

20. A tube assembly (100) according to any preceding claim, wherein the cap (50) comprises a central cap cavity (58) defined by a cap sidewall (52).

21. A tube assembly (100) according to any preceding claim, wherein the central cap cavity (58) is accessible through an aperture (56) defined in an upper surface of the cap (50).

22. A packaged tube assembly (1000), the packaged tube assembly (1000) comprising a tube assembly (100) according to any preceding claim, wherein the tube assembly (100) is contained within a sealed package (90), such as a sealed bag.

23. A packaged tube assembly (1000) according to claim 22, wherein the tube assembly (100) comprises a lyophilised reagent (91) within the reservoir (32), and wherein a desiccant (92) is provided within the sealed package (90).

24. A packaged tube assembly (1000) according to claim 22 or 23, wherein the sealed package (90) is sterilised.

25. A tube assembly (100) for processing a sample, the tube assembly (100) comprising: a container portion (10) comprising a reservoir (32) for holding a sample and processing reagents therein, anda cap (50) engaging with the container portion (10), the cap (50) comprising a sealing element (60),wherein the cap (50) is operable from an upper position in which the reservoir (32) is unsealed, to a lower, sealed position in which the reservoir (32) is sealed, and wherein the container portion (10) comprises at least one latch configured to secure the cap (50) in the lower, sealed position.

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