The present invention relates to sample containers or microtubes (hereafter "microtubes") useful in medical or other scientific analysis. More particularly, but not by way of limitation, microtubes and closures for such microtubes are described as is a method for modifying and using microtubes or closures therefor.

As used herein "microtube" refers to a container useful in medical or other scientific analysis capable of receiving a sample or substance to be retained or treated in the interior thereof. Such microtubes are, in general, small in volume when compared to flasks or test-tubes and various sizes are available, in particular: 0.5 mL and 2.0 mL microtubes are standard. However, the present invention need not be limited to such sizes and volumes more suited to a particular operation may be appropriate. Microtubes may be used for sample storage, centrifuging, assays, reactions and other medical or scientific protocols and may contain may contain diagnostics, reagents or other medical and scientific materials. For example but, of course not solely, the microtubes may find use in Polymerase Chain Reactions (PCRs). Microtubes with sealing closures are known and of these some have an additional locking mechanism to further secure the sealing closure once it is in a sealing position. These sealing closures are hinged which means that a pivoting motion is required to push the closure into place. In various protocols a sample may be placed in a microtube and then treated by, for example, freeze-drying. In these cases vapour driven off must be allowed to escape and the treated sample then protected from the atmosphere to prevent rehydration or other reactions. Known microtubes provide a flick-on/flick-off cap and it is useful to preserve this function in post drying processes and there is also an advantage in allowing the in-chamber stoppering or occluding of the microtubes to be automated.

It is against this background that one aspect of the present invention may be broadly be said to provide: A microtube comprising an operable closure cap which may engage with and substantially close an open end of the microtube characterised in that the closure cap comprises an aperture therethrough. In another aspect, it may be said to provide a microtube closure cap comprising an aperture therethrough allowing the association therewith an aperture occluding means having two modes of operation; a venting mode to allow gases, liquids or vapours to pass through the closure cap aperture and a sealing mode in which the aperture is substantially sealed. In another aspect it may be said to provide an aperture occluding means for use with a microtube or microtube closure cap.

In another aspect it may be said to provide a microtube having closure cap to substantially close the microtube and separately operable occluding means, said occluding means having two modes of operation: a venting mode to allow egress out of or ingress into the interior of the microtube and a sealing mode in which the microtube is substantially sealed.

In another aspect the present invention may broadly be said to consist in a microtube having a two stage closure: one that requires an interference fit and is thus difficult to remove; and another that may be flicked on and off by a user when the first stopper is in place, the microtube providing two modes of operation: a venting mode to allow venting of the microtube; and a sealing mode substantially sealing the microtube In another aspect the present invention may broadly be said to consist in: a microtube having closure cap with an aperture there through allowing association therewith an aperture occluding means, said aperture occluding means having two modes of operation: a venting mode to allow egress out of or ingress into the interior of the microtube and: a sealing mode in which the microtube is substantially sealed.

In yet another aspect the present invention may broadly be said to consist in: a microtube closure cap having an aperture there through allowing the association therewith aperture occluding means, said aperture occluding means having two modes of operation: a venting mode to allow only one of: egress out of or ingress into the interior of the microtube and: a sealing mode in which the microtube is substantially sealed.

In another aspect the invention may broadly be said to consist in an array of such microtubes as previously mentioned.

Preferably said array of microtubes include and matching array of aperture occluding means.

In yet a further aspect the present invention may broadly be said to consist in a method of preparing samples in microtubes comprising the steps of: providing a microtube comprising an interior and a closure cap, said closure cap preferably being able to be flicked-on and flicked-off by an user to substantially seal the microtube and separately operable occluding means, said occluding means providing at least two modes of operation: a venting mode to allow egress out of or ingress into the interior of the microtube and a sealing mode in which the microtube is substantially sealed,

introducing a substance into the interior of the microtube;

optionally treating said substance in the interior of the microtube,

placing said occluding means in the sealing mode, preferably preserving the flick-on/flick-off mode of operation of the closure cap.

Brief description of the drawings Embodiments of the invention will now be described, by way of example only, and with reference to the following drawings, in which:-

Fig 1 shows a cross-sectional view of a known microtube in an open or non- sealing condition;

Fig 2 shows a cross-sectional view of a known microtube in a closed or sealing condition;

Fig 3 shows a cross-sectional view of a microtube according to a form of the present invention with the closure cap open;

Fig 4 shows a cross-sectional view of a microtube according to a form of the present invention with the closure cap open; Fig 5 shows a cross-sectional view of a microtube according to a form of the present invention with the aperture occluding means in the venting mode of operation; Fig 6 shows a cross-sectional view of a microtube according to a form of the present invention with the aperture occluding means in the sealing mode of operation;

Fig 7 shows a plan view of the aperture in the closure cap in a form of the present invention;

Fig 8 shows a cross sectional view of the aperture in the closure cap in a form of the present invention;

Fig 9 shows a cross sectional view of an aperture occluding means according to a form of the present invention; Fig 10 shows a cross sectional view of an aperture occluding means according to an alternative form of the present invention; and

Fig 11 shows a cross sectional view of an array of microtubes according to a form of the present invention.

Known microtubes may include a press-to-seal (illustrated) or a twist-to- lock (not illustrated) closure caps and are shown in Figs 1 and 2. The sealing is usually achieved through the use of a sealing lip 13; these sealing lips can be placed in an interference fit with the opening 7 of the microtube 3. The sealing lip 13 thus must be sized and shaped appropriately and the material of the lip or the surrounding area of the microtube 3 of sufficiently resilient nature. The sealing lip 13 thus seals the microtube so as to prevent the loss of any contents and also, given the interference fit, provides a degree of locking. An additional locking or tamper evident feature may also be included; in particular, the press- to-seal form may include an additional hook 11 to provide greater security of closure and hence sealing The press-to-seal form usually further includes a hinge 12, in particular a living hinge 12 moulded out of the same material as the remainder of the microtube 3. The hinge is useful in providing a flick-on flick-off mode of operation, that is, the microtube can be held by an operator in one hand and a digit such as their thumb used to flick the cap off or into the open condition. Similarly the user can flick the cap into the closed condition. In this manner the user can operate the microtube one-handed and, in particular, the user does not have to place the microtube onto a surface where there is a danger of it being knocked over or the microtube or the content thereof damaged. Further the cap cannot be lost or contaminated from any alien surface on which it is placed as it is retained on the microtube. In forms of the invention the flick-on, flick-off operation of the cap is retained. Such hinges 12 and locking devices 1 provide a useful function but also limit how closely such microtubes can be packed together in arrays, especially when the lids are in the open position. Further, as the cap must be pivoted around the axis of the hinge 12 in order to close a simple application of vertical force cannot be used to facilitate such closure and so more complicated automation is required to close such microtubes and, in particular, a simple vertically translating plate cannot provide such automation. Such microtubes 3 as described and illustrated herein should be capable of withstanding the protocols inherent in the medical industry. These may include boiling or otherwise heating or irradiating of the microtube 3 or contents therein, deep freezing or freeze drying, centrifuging or interaction with reacting solutions. The protocols that require freezing generally result in known conventional microtubes popping open when the samples are thawed. It is therefore important that the microtube 3 and closure cap 4 be positively lockable and resist unlocking or unsealing during such treatment.

Referring to the drawings, it will be seen that the microtube 3 assembly including the closure cap is designated generally by the numeral 2, the microtube being designated generally by the numeral 3, while the closure cap tethered integrally to the microtube 3 is designated generally by the numeral 4

From the figures, it will be seen that the microtube 3 is formed often by moulding from any of several appropriate materials, commonly "plastics" or suitable resinous substances, in other cases the microtube may be produced from glass. A microtube 3 may include an elongated tubular cylindrical body 3 having walls 6 that extend from an open end 7 to a closed end 8. As shown in the drawings, in some forms, the closed end of the tubular body is conically formed to define a reservoir or interior 9 having a progressively diminishing capacity that is helpful in collecting the last vestige of a liquid sample that is contained in the tube, thus facilitating its removal by aspiration through a syringe needle or pipette. In other forms (not shown) the microtube 3 may have a flat end or base. Those skilled in the art to which the invention relates will appreciate that other shapes are possible, such as an ampoule or a flask, what is required is a hollow body capable of receiving and containing the sample or other substance.

As can be seen from the figures, in one form the present invention comprises a microtube 3 having closure cap 4 with an aperture 45 there through. Such an aperture 45 allows the association of an aperture occluding means 40 with the closure cap, in some forms of the present invention such association may simply comprise the placement of the aperture occluding means in the aperture 45 such that it is weakly retained. In other forms of the present invention stronger retention may be achieved through the aperture occluding means 40 passing through the aperture 45 and expanding into the interior of the aperture occluding means and of the microtube, this could be through having an expanding portion of the aperture occluding means or through use of a resistant material that is squeezed through the aperture and then allowed to expand towards its former size and shape. Further, said aperture occluding means 40 has two modes of operation: a first venting mode to allow only one of: egress out of or ingress into the interior 9 of the microtube. Therefore in this mode, for example, substances such as gas can be expelled from the microtube 3 or substances are able to enter into the interior 9 of the microtube 3 through the aperture occluding means 40. This allows, for example, gases, such as water vapour, to be driven off the sample in the microtube 3 and to vent into the atmosphere or, in other cases, a substance such as, for example, an inert gas such as Nitrogen to be forced into or backfill the microtube 3 so as to surround the sample. In the former case this may be required when using techniques such as freeze drying and in the latter may be relevant when protecting the sample form such potential problems as oxidation when heated.

The venting mode may be achieved by, for example, providing a narrow channel adjacent an edge of the aperture occluding means 40 in the situation that the aperture occluding means 40 is made of a resilient material such as, for example, a suitable rubber or plastics material. In other forms of the invention multiple channels may be present and these may take the form of flutes. In order forms of the invention the valve means in provided by a conduit 41 through the aperture occluding means 40, the conduit 41 being substantially open to allow ingress or egress as required. The aperture occluding means may be provided individually or in strips or arrays. The multiple form of the aperture occluding means may facilitate automatic positioning and placement, that is, means may be provided to install the aperture occluding means in the aperture of the microtube by machine, either a number simultaneously or serially with one being place after another.

The second mode provided by the aperture occluding means is a sealing mode in which the microtube 3 tube is substantially sealed, for example by fully occluding the aperture in the closure cap. In this mode the microtube is effectively stoppered. In one form of the invention this is achieved by means of the material properties of the aperture occluding means. For example the aperture occluding means may be formed of a resilient material, such as, rubber, thus allowing a portion of slightly greater cross section than the aperture to be forced there into. In other forms the material may be of a less resilient type but still allow an interference type fit into the aperture. In other forms it may be the material surrounding the aperture in sealing means that allows such interaction. In this mode the venting allowed in the venting mode no longer occurs. In forms of the invention having channels or flutes 42 this may be achieved by means of the channels or flutes 42 closing as the aperture occluding means 40 is forced into the aperture 45. In the form of the invention in which a conduit 41 is provided similarly the conduit 41 may be closed as it is squeezed into the aperture 45. In other forms of the inventions (not shown) a mechanical valve may be provided with means whereby the venting mode is shut off. This may comprise a simple one-way valve positioned to allow venting from the microtube and which is capable of being closed so that it substantially seals the microtube as required, for example it may comprise a ball valve.

The use of microtubes according to at least one embodiment of the present invention will now be described. The microtube 3 is placed so that they can receive samples. In some forms this may involve placement in a rack, in some known forms such racks have a capacity of 96 microtubes 3. However, such a size is merely convention and others are available or possible. In some cases the dimensions of the rack are standardised and thus the number of microtubes 3 that can be fitted into such a rack depends on their size and shape and thus how closely they can be packed together. For example, hinges or locking mechanisms may extend from the microtube 3 thus providing a limit to how closely one can be placed beside another. Other sizes and capacities of racks are available and this may depend on the amount of surrounding area required for access around the microtube 3. The rack may comprise a series of spaced indents to hold microtubes 3 in a substantially vertical manner or it may be more provide a more sophisticated manner of holding or retaining the microtubes 3. Further the microtubes 3 may be attached together in a strip, such strip may be formed by means of a separate member 20 having appropriate apertures there through or it may be produced by means of extensions to the microtubes interconnecting to each other (not shown). Such strip 20 may be linear, that is, provide microtubes in a line or may form an array, and that is, the microtubes may abut each other in two substantially perpendicular directions. Figure 11 shows a small number of such microtubes 3 side by side but one skilled in the art to which the invention relates will appreciate that arrangements of many more microtubes 3 are possible both in one and in two dimensions. The sample or samples are then introduced into the interior 9 of the microtubes 3 either by hand or machine. The technique used may be pipetting or other means whereby the required amount of substance is placed into interior 9 of one or more microtubes 3. The substance may, of course, comprise a solid, liquid or mixture thereof and the technique is thus chosen as appropriate to the sample.

At least one form the present invention can be used in a freeze drying process wherein the substance to be freeze dried is placed in the interior 9 of the microtube 3, this can be facilitated by opening the closure cap, if necessary the closure cap may then be closed and in some forms the locking mechanism locked in place. The aperture occluding means 40 is then placed in venting mode whereby egress out of or ingress into the interior of the microtube 3 is allowed. In forms of the invention multiple such microtubes may be racked together in an array, see figure 11.

The microtubes 3, substances to be freeze-dried and any associated rack is then freeze dried with the occluding means allowing vapor to be driven off the substance to be freeze dried and out of the microtube 3. When the substance to be freeze-dried has achieved a sufficient dryness the occluding means 40 can be placed in the sealing mode thus sealing the microtubes 3. In preferred forms of the present invention this is achieved on multiple microtubes according to the present invention by using automated process, such as, the use of a vertically moving plate to apply a force substantially in the direction of the long axis of the microtubes. In other forms of the invention this procedure may be applied to individual tubes one after the other or by hand. The microtubes 3 are thus sealed W and the substances or samples therein will absorb less moisture from the atmosphere than if they were not.

One skilled in the art to which the invention relates will realize that similar methods can be used in conjunction with protocols in which fluids other than water or driven off an substance placed or otherwise present within the microtube. In other cases the interior of the microtube 3 is flushed with, for example, an inert gas or the substance placed or otherwise contained within the microtube 3 is blanketed with such a gas whilst the aperture sealing means is in the venting mode. These techniques may be useful in protocols in which reaction of the substance contained with the microtube 3 is preferably reduced or limited.

In preferred forms of the invention the closure cap can be used to open the microtube 3 with the aperture occluding means in place thus allowing access to the interior of the microtube, similarly the microtube 3 can be resealed using the closure cap. This may find use when a stage of testing or analysis has taken place or, for example, to dispose of the contents of the microtube 3 after all testing has taken place. The opening of the closure cap as shown in figure 4 enables ready access to be made of the interior 9 of the microtube 3 and in some cases devices such as pipettes can be used as required. In the situation where further testing is to take place the closure cap remains attached to the microtube 3 and thus will not be lost.

In some forms of the invention the sealing modes of the aperture occluding means 40 can be provided using a mechanism or preferably an automated mechanism to urge the aperture occluding means into the aperture. The aperture occluding means 40 may be placed in the sealing mode by applying downward pressure and as this is preferably in a direction parallel to the axis of the aperture (and in the case as shown in the figures parallel to the long axis of the microtube 3) and orthogonal to the rack the microtubes may be in, it is thus a simple matter to provide a traversing plate to seal a number of microtubes according to a form of the present invention in a rack or similar simultaneously.

In one embodiment of the present invention existing sealing caps for microtubes may be modified or retrofitted by means of creating an aperture 45 in the sealing cap, this may be achieved by, for example, drilling, laser or water cutting or punching, in other cases an annulus cap may be moulded to provide an apertured cap and in some cases the cap may be capable of being placed on a microtube the has previously used a cap without such an aperture. If required, the edge exposed by such an operation may be smoothed by techniques which be known to one skilled in the art to which the invention relates. In other forms the aperture 45 may be moulded as part of the manufacturing process by, for example, injection moulding the annulus cap.

Further, a microtube closure cap 4 may be provided to be fitted on to a microtube. Such a cap has an aperture 45 to allow it to be associated with aperture occluding means 40. Similarly to other forms of the invention the aperture occluding means 40 has two modes of operation: a first a venting mode to allow egress out of or ingress into the interior of the microtube. The substance allowed to ingress or egress is preferably vapour such as water vapour but may be other suitable substances, such as gas or other fluids that may be driven off or otherwise produced by the substance contained within the interior 9 of the microtube 3. The aperture occluding means 40 further includes a sealing mode in which the microtube 3 is substantially sealed to; for example, prevent moisture in the atmosphere rehydrating a dried, for example, freeze-dried substance contained within the interior 9 of the microtube 3.

In forms of the invention as shown in figure 4 the closure cap 4 can be removed, additional tests or reactions performed on the substance or sample and the closure cap replaced as shown in figure 6 without have to remove the aperture occluding means 40 which could be in a very tight interference fit or otherwise difficult to remove due to its size, position or shape.

With current standard prior art microtubes, a typical procedure using microtubes may comprise the following steps:

1/ pick up microtube;

21 pipette material into the microtube;

31 place the microtube in a rack;

4/ repeat steps 1 -3 for as many samples as required;

5/ place rack of microtubes in processing area such as freeze-drying compartment, heating chamber, gas chamber - and start process;

6/ then either:

/ remove microtubes one by one from rack and flick closed with thumb;

or

ii/ initiate complex mechanism to close microtube cap or caps;

71 subsequently, access contents of microtube by flicking cap open for further processing steps such as testing, disposal of contents, and so on.

The advantage of the current invention is that it allows for the easy automation of at least step 6 of the above methodology and overcomes at least one disadvantage of the prior art methodology, which is that if an array of microtubes sits in a rack with the lids open, then the distance between the microtubes must be sufficient to allow for the presence of the lids. It is necessary for the lids to remain open for some processes where water vapour or other gases are required to escape from or flow into the tubes. Further, any automation of the lid-closing procedure requires a very complex machine and the orientation of the microtubes in the rack must be quite precise. Also, if the lids are subsequently closed manually as described in stage 6/i/ above, there is a greater risk of contamination and/or accidental spillage of contents due to the manual intervention.

An array of microtubes according to the current invention may be prepared with the lids already closed, thus allowing for tight packing in an array in a rack. An automated pipette system may then be used to place material in the microtubes through the aperture in the lid. The aperture occluding means can then be added by a further automated system, which would be relatively simple as a mere axial force along the axis of the microtubes would be required to insert the aperture occluding means within the aperture. It will be readily appreciated by those skilled in the art of automation that a variety of automated means may be provided to achieve this. The system can be set up for either full insertion of the occluding means, thus sealing the microtubes altogether, or partial insertion, leaving the venting channels or flutes open to allow vapors or gases to enter or leave the microtubes, depending on the next process desired. This also reduces the risk of contamination or accidental spillage which may be caused by manual intervention, as usual in prior art microtubes. However, the possibility still remains for the occluding means itself to be manually operated should this be procedurally appropriate. W

For ease of laboratory use, microtubes in accordance with the current invention could be provided in a number of states; individually with lids open or closed, with or without separate occluding means provided; individually with lids open or closed and occluding means in place, in venting or non-venting position; in an array, potentially in a rack, with lids open or closed, with or without sets of occluding means provided; in an array, potentially in a rack, with lids open or closed and occluding means in place, in venting or non-venting position. Accordingly can be seen a major advantage of the invention in that it can be provided in a number of states, or used in a variety of processes, according to the process requirements of the user. Further, there is always the possibility at some or any stage of a process, whatever the state of the aperture occluding means, to manually operate the lid in the normal fashion of prior art microtubes by 'flicking' the lid on or off with a digit.

By way of example only, and in a preferred embodiment of one aspect of the invention, the invention is used in a freeze-drying process. Material is pipetted into the microtubes, either manually or automatically, individually or in an array, as previously described, and after this procedure the microtubes are thus present in an array in a rack with the lids closed and the occluding means present, with the occluding means in the venting position. The rack is then placed in a freeze-drying environment, and gasses are able to access or egress the microtubes via the venting channels. Once the freeze-drying is complete, an automated device such as a vertically translating plate presses down upon the array, simultaneously pushing the occluding means of all the microtubes into the closed position and thus sealing the microtubes. As an alternative the array is lifted up by lifting means to press against a static plate to achieve the same result. Later on, any microtube is accessible by a user by simply flicking the lid into the open position.

The aperture therethrough as described herein and in the preceding text is envisaged as being a hole with a complete circumference or other defining edge, as illustrated in the accompanying figures of one embodiment which show it as a circular hole in the operable closure cap. In the accompanying figures, the cap, with its aperture therethrough, is essentially in the form of an annulus when seen from above. Whilst the aperture need not be circular, nor need it be central to the cap, it is clear that the aperture therethrough as described hereinbefore is not simply a groove or notch at the outer edge of the cap.

The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one skilled in the art to which the invention relates. Each and every of these alternatives and variations are intended to be included within the scope of the following claims where the term "comprising" means "including, but not limited to". Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.

Having described particular preferred embodiments of the present invention, it is to be appreciated that the embodiments referred to are exemplary only and that variations and modifications may be made without departing from the scope of the invention as set forth in the appended claims. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.