NZ543824A - Micro Organism Testing Device - Google Patents

Abstract

A micro-organism testing device is disclosed. The device 1 comprises a resealable container 2, 4, 11 under reduced pressure containing a growth medium and a cap 3 to capture the resealable portion of the container. The cap is provided with internal means adapted to puncture the resealable portion of the container. The cap is moveable between a first and a scond position wherein travel of the cap between the first and second positions will cause the internal means to puncture the resealable portion of the container.

Description

Patents Form # 5 INTELLECTUAL PROPERTY OFFICE OF N.Z. 2 9 NOV 2006 RECEIVED NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL # : 543824 DATED : 29 November 2005 TITLE : Screw Activated Rcmovcablc Spike ii"*- I<£-*» ^ c-€_ I, SHARPIN, Rosemary Katherine Cameron Address: 31a Lucerne Road, Remuera, Auckland, New Zealand, 1050 Nationality: A New Zealand citizen do hereby declare the invention for which I pray that a patent may be granted to me and the method by which it is to be performed, to be particularly described in and by the following statement: 170602NZ_Cap_20061128_ 945_AERdoc FEE CODE 1050 B1ELD OF THE INVENTION The present invention relates to improvements in and relating to a micro-organism testing device in particular but not exclusively to a device adapted to receive a fluid test sample.

BACKGROUND ART KNOWN TO THE APPLICANT The contamination of foodstuffs, additives, cosmetics, pharmaceuticals and the like by undesirable micro-organisms represents a significant threat to public health. In the past, a number of methods to monitor the presence of such micro-organisms in foodstuffs, water supplies, emulsions (e.g milk), fluids in general and on food preparation surfaces have been developed. Generally such methods rely on conventional microbiological techniques, 10 typically including the growth of micro-organisms on selective nutrient solid support media or alternatively in selective nutrient media. Subsequent morphological analyses are then carried out.

One such technique currently carried out by the Applicant involves the use of a growth medium already stored in an evacuated UV light non-penetrative, clear plastics container that 15 is sealed with a rubber septum. The liquid sample to be tested is introduced into the container through the septum via a needle or some other form of cannula, the pressure difference ensuring that the sample is "sucked" into the container. The sample is then incubated and tested for specific or broad types of micro-organisms using Infra Red, Ultra Violet or visible light. Contamination is always a potential problem using such a technique.

By necessity, some of these testing techniques tend to be carried out on products just before they are to be sent into the marketplace and these products cannot enter the market place until the results are back from the testing laboratories.

In respect of products for human consumption, some of the methods employed to remove any residual harmful bacteria have usually just taken place and thus, not too surprisingly, the 25 level of bacteria that the testing techniques are designed to look for is so low that the test result for this bacteria is "negative". As such, the product is passed fit for human consumption.

However, the bacteria although present in un-detectably small quantities are nevertheless still present and multiply and under the right conditions, given the shelf life of the product, may 170602NZ Psl 20061123 929 ADC.doc/JWP/ADC Received at IPONZ on 27 May 2008 be able to recover to the extent that the bacteria are suddenly present in sufficient quantity to cause harm once the product is consumed.

This problem of "shelf life recovery" is a serious one in many types of industry and very few solutions to this problem apart from limiting the shelf life of the product to a very small time 5 frame have been proposed.

Furthermore, the micro-organism testing kits (of the type described above) have relatively low shelf lives as UV light tends to kill the growth medium contained therein. In addition, the material once tested may or may not be a bio-hazard and disposal of such materials is expensive and legislation in this area is only ever going to increase the cost of disposal of 10 such materials.

It is an object of the present invention to try and alleviate at least some of the aforementioned problems or at least to provide the public with a useful choice.

STATEMENTS OF THE INVENTION According to a first aspect of the present invention there is provided a micro-organism 15 testing device comprising a resealable container under vacuum and a cap adapted to be held in a first position on the container, the cap being provided with internal means adapted to puncture a resealable portion of the container and the cap being moveable between a first position and second position, wherein travel of the cap between the first and second positions will cause the internal means to puncture the resealable portion of the container.

Such an arrangement minimises contact with the internal means and provides a cover for the resealable portion thus reducing the possibility of it being contaminated with anything.

Preferably the internal means is a needle or cannula.

Preferably the device is provided with visual means of indication to determine whether the device is under a reduced pressure.

More preferably the needle or cannula has more than one aperture. The Applicant has found that an ordinary single apertured cannula or needle may get "bunged up" especially if the liquid sample is thick. However, multiple apertures (usually two but there could be three or 170602NZ Psl 20061123 929 ADC.doc/JWP/ADC four) tend to overcome this potential problem. For best results, the apertures are usually opposite each other on the cannula or needle.

Preferably the container contains a growth medium.

The movement of the cap between the first and second positions could be a rotary or linear 5 movement however it is preferable if the movement of the cap causes the internal means to travel along a path substantially parallel or coaxial with the principal axis of the device.

Preferably the resealable container is a multi-compartment resealable container.

If the container is a multi compartment container, then preferably each compartment is separated by a barrier whose removal or puncture will allow communication between these 10 compartments to take place.

The or each compartment may be under vacuum. However, preferably, at least one compartment of the container is under vacuum.

The or each compartment may contain a growth medium however, preferably, at least one compartment contains a growth medium and at least one other compartment contains a 15 growth medium additive.

The device in use will suffer a build up of pressure during use through gases emitted from any micro-organisms present under test. Thus the walls of the device and any other internal structural aspect of the device must be built to withstand such a build up of pressure.

Preferably the growth medium additive is a sanitizing agent such as bleach. Once the growth 20 medium additive has been allowed to mix with a sample under test the sample under test changes from a potential bio-hazard to a chemical hazard. Such a chemical hazard is easier to dispose of, the bleach having rendered the bio-hazard safe.

Preferably the growth medium additive incorporates a dye. The dye may be green or black to provide a positive visual indicator that the growth medium additive has been successfully 25 added to the container containing the sample under test.

The device may be colour coded. For example the base of the device may be coloured the same colour as a positive test for the presence of a particular micro-organism. This will serve 1706Q2NZ Psl 20061123 929 ADC.doc/JWP/ADC as a visual indicator to an individual using the device that he/she has found the presence of that particular micro-organism. For example the presence of ecoli may be pink using a particular type of growth medium and so the base of the device for example may be coloured substantially an identical colour pink.

The growth medium will be dependent upon what is being tested for. Typically the test is going to be for a micro-organism in thwe form of a bacterium such as faecal coliform and/or ecoli and growth media that is specific for these types of bacteria will be used.

Preferably the device is provided with a stop member to prevent accidental movement of the cap between the first and second position. Such a device may be a removable snap fit clip.

More preferably the stop member may be integral with the device. Thus movement of a lever about a pivot could first unlock or otherwise remove the stop member allowing movement of the cap between first and second positions to take place and then continued movement of the lever could actuate this movement. Alternatively the cap and container may be provided with complementary stop members and movement of one relative to the other may be required to 15 allow subsequent movement of first and second members More preferably the cap and container are provided with complementary stop members to prevent accidental movement of the cap between the first and second position.

More preferably still movement of the cap relative to the container in a direction substantially oblique or orthogonal to the line of travel between first and second positions is 20 first required to disengage said respective stop members.

Preferably the resealable portion of the container comprises a septum whose internal side walls are provided with a taper. This has the advantage that a needle or cannula piercing the septum does not need to hit the top of the septum at exactly 90 degrees to the septum but could hit it at substantially 90 degrees and still pierce the septum and allow the device to 25 function properly.

Preferably the device incorporates alphanumeric characters. Many people who may be illiterate still recognise the square "stop" and side ways triangle "play" character on a tape, video or DVD player. As such it may be advantageous to use similar characters on the device of the present invention to assist a user of the device. 170602NZ Psl 20061123 929 ADC.doo/JWP/ADC The invention includes within its scope a micro-organism testing device substantially as herein described with reference to and/or as illustrated in any appropriate selection or combination of the accompanying drawings.

The invention further includes within its scope apparatus adapted to receive and/or otherwise 5 incorporating a micro-organism testing device of the present invention.

The device is prepared with the cap fitted to the container and then in this arrangement the device is shrink wrap sealed in plastics material and the device is then subjected to irradiation to sterilise the device. Just prior to use the shrink wrapping is removed. As the cap captures the resealable portion no physical contact of the means adapted to puncture the 10 resealable portion of the resealable portion by a user takes place during travel between first and second positions thus minimising any potential contamination of the sample to be tested.

BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the present invention will now be more particularly described, by way of example only, with reference to the accompanying sheets of drawings in which: Figure 1 illustrates a front view of a container and cap embodying the present invention.

Figure 2 illustrates a rear view of the container and cap illustrated in figure 1.

Figure 3 illustrates a sectional view of the container and cap through its longitudinal axis.

Figure 4 illustrates front and side views of the screw threaded neck portion of the container.

Figure 5 illustrates a top view of the container.

Figure 6 illustrates a side view of a septum used with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Figure 1 shows a ready to use micro-organism testing device in the form of a sample bottle and cap that is generally referenced 1.

The device 1 comprises a polyethylene two compartment container (2,4), (the smaller of the 25 two compartments being coloured and the larger of the two compartments although 1706G2NZ Psl 20061123 929 ADC.doc/JWP/ADC transparent being adapted to be non UV transparent) and a coloured non transparent polyethylene cap 3. Each compartment (2,4) is coaxial with the principal axis of the device 1 and has substantially identical radii. The smaller of the two compartments 4 forms a base of the device 1 upon which the device 1 vertically stands in its normal attitude of operation. The 5 larger of the compartments 2 is located above the base portion 4 extends upwards to form a body of the device 1.

As one travels up the body of compartment 2, the upper portion of the body tapers radially to provide the top of the body with a domed shaped top 11. On top of the dome 11 of the body and coaxial with the principal axis is an upwardly extending integral neck portion 10. The 10 neck portion 10 is provided with an external screw thread 5.

The external screw thread 5 consists of three threads 5 each possessing a helix angle of substantially 40°. The relationship between the diameter of the neck portion 10 and the pitch of the thread 5 is such that the maximum circumferential angle swept out by one of the threads 5 from its start at the top of the neck portion 10 to its finish at the base of the neck 15 portion 10 is 270°.

The overall neck portion diameter of the device 1 is defined as the neck portion diameter plus the additional diameter provided by the screw thread 5. The additional length in diameter provided by (twice the thickness of) the screw thread 5 is defined as the major diameter of the screw thread minus the minor diameter of the screw thread. The minor 20 diameter of the screw thread is to all intents and purposes the neck portion diameter.

When viewed from above, (fig 5) the substantially circular neck portion 10 of the device 1 is seen to be provided with opposing parallel straight (or flat) sections 9 which give the impression that the circumference of the neck portion 10 has been "sliced" through (similar to a line defined by a cord of a circle and the smaller portion of the circle to one side of the 25 cord having been removed) passing through the entire length of the neck portion 10 and the threads 5 interrupting the threads 5 that the straight sections 9 pass through..

Each "slice" of the flat section 9 is to a depth defined substantially by the distance obtained by subtracting the minor diameter of the thread from the major diameter of the thread and dividing the number obtained by two. 170602NZ Psl 20061123 929 ADC.doc/JWP/ADC Radially extending from and parallel with the top of the neck portion 10 and of similar dimensions to the threads 5 are a pair of stop member threads 30 that have a helix angle of zero degrees substantially 120° apart that extend part way about the top of the neck portion 10 and are integral with the threads 5. These stop members can be seen clearly in figures 3 & 5 4.

Travelling up from the top of the neck portion 10 the radius of the body 2 tapers rapidly for a short distance to produce a trumpet shaped shoulder and then the start of a coaxial upwardly extending collet 12 of constant radii begins. This collet 12 terminates at its top with a circular flange 14.

Coaxial with the principal axis and located on top of the flange 14 is a circular rubber septum 13 of similar dimensions to the flange. The septum 13 is integrally fitted to the flange 14 by a circular aluminium sleeve whose respective ends have been crimped around the flange 14 and upper circumferential peripheral surface of the septum 13 to provide a substantially air tight seal and which exposes a circular upper surface of the septum 13.

As there are three threads 5 on the neck portion 10, the internal circumferential face of the cap 3 is also provided with three complementary threads 15. These three threads 15 form the external screw thread for the cap 3. The start of each of these threads 15 occurs at the same base line of the cap 3 but they each occur substantially equidistant from each other. The threads 15 extend vertically upwards for a distance substantially equal to height of the neck portion 10.

Downwardly depending from the inner upper surface of the cap 3 is a cylindrical sleeve 16 that is coaxial with the principal axis and which possesses an internal diameter whose dimensions are such as to provide a friction fit of the sleeve 16 over the crimping material sleeve. The height of the sleeve 16 is substantially equal to the height of the collet 12.

The cap 3 is dome shaped and the tip of the dome is in the form of a frusto-conical apertured trumpet shaped extension 18 that extends upwards a short distance terminating in a flat external circular mouth. The end of the dome shape of the cap 3 and the start of the extension 18 is defined by a point of inflection as one travels up the dome towards the flat circular mouth. The internal diameter of this extension 18 is substantially constant throughout its length and acts as a reinforcing and stabilising member for a cannula 17 located within the 170602NZ Psl 20061123 929 ADC.doc/JWP/ADC cap 3. The exterior surface of the cap 3 is provided with a plurality of spaced apart parallel downwardly depending integral ribs 6 which may be considered as cap strengthening ribs and finger grips for the cap 3.

The cap 3 is also provided with an embossed alpha numeric consisting of the number "1" 5 followed by a 'sideways triangle' reminiscent of the 'play button' on a tape, video or DVD player (or recorder).

The cannula 17 formed from polypropylene material and differently coloured from the cap 3 may be considered to be a straight elongate tube provided with a proximal and distal end. The distal end is provided with a sharp tip adapted to pierce the septum 13. Substantially 10 midway between the ends of the cannula 17 is a radially extending circular flange 60 of uniform thickness.

The flange 60 is adapted to sit within a countersunk groove located coaxially with the principal axis of the device 1 at the internal mouth of the trumpet shaped extension 18 of the cap 3. The proximal end of an elongate silicone sleeve or tubing 20 is adapted to enter the 15 flat external mouth and fit within the apertured top of the cap 3 and subsequently pass over the proximal end 19 of the cannula 17 up to the upper surface of the flange of the cannula in a friction fit manner.

Once the flange 60 of the cannula 17 is located within the countersunk groove in the cap 3 the upper proximal end portion of the cannula 17 extends out beyond the external mouth of 20 extension 18 of the cap 3. Furthermore, the outer diameter of the silicone tubing 20 is similar to the internal diameter of the extension 18 forming a substantially air tight seal with it once the cannula 17 has been pushed into the silicone tubing 20 expanding it slightly.

The silicone tubing 20 is provided with a plurality of parallel equally spaced apart radially extending circular reinforcing ribs 21 each of similar dimensions that begin just after the 25 proximal end 19 of the cannula 17 stops and terminate substantially once the tubing 20 has been folded through 180° back onto itself. The tubing 20 then passes down the exterior face of the cap 3 and is locked into place by a substantially "c" shaped locking member 22 that is integral with and projects radially from the base of the cap 3 and captures the tubing 20. 170602NZ Psl 20061123 929 ADC.doc/JWP/ADC A pair of parallel equally spaced apart radially extending circular reinforcing ribs 21 each of similar dimensions and each of similar dimensions to the ribs 21 are located above and below the portion of the tubing 20 that is intended to be captured by the "c" shaped locking member 22. The distal end portion of the silicone sleeve 20 is provided with a trumpet 5 shaped flange 50. The flange 50 acts as a stop member for a polypropylene needle capping member 51. Located a little way beyond the flange 50 is the mouth and lips of the distal end of the silicone tubing 20.

Incorporated integrally within the distal end portion is a needle capping member and extending from this member and out of the mouth of the distal end portion of the silicone 10 tubing 20 is a stainless steel needle which prior to use is capped by the needle capping member 51, the open end of which passes over the lips of the mouth of the distal end portion of the silicone tubing 20 in a 'friction fit' manner eventually abuting the 'stop member' end of the flange 50 The compartment 4 is formed when three components come together, a base portion, a foils 15 sheet 25 and a bleaching solution containing dye.

The base portion is provided with an upwardly projecting hollow column 40 that extends from the internal base surface of the compartment 4. Within the 'well' created by the hollow column 40 is placed a solution of bleach together with a green dye. A sheet of circular foil 25 that has a thin layer of bonding material applied uniformly across both sides of the foil sheet 20 surface is then "bonded/welded/glued" about its circumferential periphery via an induction welding process to the upper surface of the rim of the column 40 to form a fluid tight seal. Compartment 4 is now formed.

The compartment 4 is pink in colour and the exterior surface of the base of the compartment 4 is provided with an embossed numeral '2' followed by a 'square' reminiscent of the 'stop' 25 button on a tape, video or DVD player (or recorder).

The interior side walls of the compartment 4 (that possess a greater diameter than the column 40) are provided with a screw thread 27. The lower side walls of the compartment 2 are provided with an external screw thread 28 that is complementary to the screw thread 27. 1706Q2NZ Psl 20061123 929 ADC.doo/JWP/ADC To fully form compartment 2, two things need to occur, the septum 13 needs to be crimped onto the flange 14 and compartment 4 needs to become integral with the 'compartment 2'.

When 'compartment 2' and compartment 4 are screwed together via mating screw threads 27 and 28, the glue present on the upper surface of the foil sheet 25 in compartment 4 contacts a 5 circumferential base rim 29 of the 'compartment 2' and through induction welding again, the foil sheet 25 becomes integral with both compartment 2 (now fully formed) and compartment 4.

A resilient circular convex diaphragm 23 of smaller diameter than and coaxial with the column 40 forms part of the base of the 'well' of the column 40. The upper surface of the 10 diaphragm 23 is s provided with a set of circular upwardly projecting 'saw tooth' teeth 24 that are also coaxial with the column 40 and principal axis of the device 1. The teeth 24 are adapted to puncture the foil sheet 25 that spans the surface area swept out by the rim 29.

The exterior surface of the diaphragm 23 is recessed within the flat base 26 of compartment 4 such that the exterior surface centre of the diaphragm sits above the flat base 26 of the 15 device 1. This arrangement tends to reduce accidental depression of the diaphragm 23 if the device 1 is sat on a flat surface in its intended attitude of operation.

The compartment 2 is then provided with a growth medium (in this case the growth medium is intended to test for ecoli) and then compartment 2 is sufficiently evacuated to leave a vacuum capable of drawing into compartment 2 (within a degree of experimental tolerance) 20 100ml of test solution. The reduced pressure within compartment 2 will also tend to draw the foil sheet 25 up and into the body of compartment 2 (by a small degree) and further away from the teeth 24. The design of the septum 13 is such that prior to evacuation the upper surface of the septum 13 sits proud of the crimping material 14 in the form of a substantially convex bulge.

Upon evacuation of air from the device, the septum 13 is 'sucked' in towards the base of the device 1 with the result that convex bulge now becomes a concave depression. This concave depression would provide a user of the device 1 with a visual indication that the device 1 is usable and indeed ready for use (if the cap 3 was transparent). It at least provides the manufacturer of the device 1 that the container 2,4 is under reduced pressure. 170602NZ Psl 20061123 929 ADC.doc/JWP/ADC Received at IPONZ on 27 May 2008 The cap 3 is then pushed onto the container 2,4 and at least one of the three threads 15 will contact the stops members 30 preventing any further downward travel of the cap 3. The distal end of the cannula 17 will now sit above the septum 13 but will not pierce it. The silicone tubing 20 is pushed into locking member 22.

The device 1 is then sealed in shrink wrap plastics material and irradiated sterilising it completely.

Turning briefly to figure 6, this shows the rubber septum 13 in more detail. As can be seen the neck 70 of the septum 13 that is in contiguous contact with the internal walls of the collet 12 when in use is provided with tapered walls 71 so that the cannula 17 need not have to 10 pierce the septum 13 at exactly 90 degrees to the top surface of the septum 13. Instead, there is a degree of 'play' available on account of the sloping walls 71.

In use, the shrink wrap material is removed.

The cap 51 is removed.

The silicone tubing is released from the locking member 22.

The device 1 is inverted and the stainless steel needle is inserted into the liquid sample (which is probably held within the confines of a membrane and the needle will pass through that).

The cap 3 is then simultaneously pushed towards the container 2,4 and rotated in a clockwise direction (pressing '1' the 'start' button). Such an action will inevitably cause the threads 15 20 to locate with the flat sections 9 enabling further travel of the cap 3 towards the container 2,4 via the complementary screw threads 5 to take place. Such travel towards the container 2,4 will cause the distal end of the cannula 17 to pierce the septum 13 and further travel within the collet 12.

As a result of the pressure differential that exists between compartment 2 and the ambient 25 pressure external to the device 1, liquid sample (to the tune of 100ml) will be drawn into compartment 2. Once pressures between the compartment 2 and the outside world have been equalised, the cap 3 is rotated counter clockwise and removed from the device 1. Any sample remaining within the silicone tubing 20 is superfluous to requirement as the pressure 170602NZ_Ps 1 _20061123_ 929_ADC.doc/JWP/ADC differential that exists within compartment 2 of the device 1 prior to use is so designed as to take sample trapped within the silicone tubing 20 into account when sample collection is being obtained.

The sample bottle is then shaken to allow the growth medium to mix thoroughly with the 5 sample and the sample bottle is then incubated. Apparatus and other means to incubate the sample will be known to the person skilled in the art but a preferred apparatus to incubate and test the sample is disclosed in PCT/NZ2005000139 and the disclosure of the apparatus and all other relevant information relating to the same is hereby imported into this specification.

Once testing has been completed (in this case a test for ecoli, which a visual test is pink the same colour of the compartment 4 of the device 1, depression of the convex diaphragm 23 (pressing '2' the stop button) causes teeth 24 to rupture the foil sheet 25 causing the test sample in compartment 2 to mix (and change colour with) the bleach/dye mixture contained in compartment 4. The visual colour change will be an indicator to those concerned that any 15 potential bio hazard present within the sample has been converted to a chemical hazard and can thus be treated and disposed of as chemical waste.

In alternative embodiments not illustrated, the silicone tubing 20 need not incorporate a stainless steel needle and needle holding member thus enabling the device 1 to be used for testing more viscous fluids or fluid samples not contained within a membrane for example 20 water samples from rivers. Furthermore the colour of the cap 3 may be varied to denote a particular type of growth medium present within the device 1.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The 25 disclosures and the description herein are purely illustrative and are not intended to be in any way limiting.

Throughout the description and claims of this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps. Furthermore, throughout this specification, 30 the use of the word "integral" is intended to cover not only something which is formed from 1706Q2NZ Psl 20061123 929 ADC.doc/JWP/ADC the outset as one single-entity component, but also anything which, whilst being assembled from a plurality of initially disparately produced integers, ends up as one overall and normally non-dismantleable structure. 170602NZ Psl 20061123 929 ADC.doc/JWP/ADC Received at IPONZ on 27 May 2008

Claims (14)

1. A micro-organism testing device comprising a resealable container under reduced pressure containing a growth medium and a cap adapted to be held in a first position on the container, the cap being provided with internal means adapted to puncture a 5 resealable portion of the container and the cap being moveable between a first position and second position, wherein travel of the cap between the first and second positions will cause the internal means to puncture the resealable portion of the container.

2. A device as claimed in claim 1, wherein the internal means is a cannula.

3. A device as claimed in claim 1 or claim 2, wherein the device is provided with a visual 10 means indicating whether the device is under a reduced pressure.

4. A device as claimed in any preceding claim, wherein the movement of the cap causes the internal means to travel along a path substantially parallel or coaxial with the principal axis of the device.

5. A device as claimed in any preceding claim, wherein the resealable container is a 15 multi-compartment resealable container.

6. A device as claimed in claim 5, wherein each compartment is separated by a barrier whose removal or puncture will allow communication between these compartments to take place.

7. A device as claimed in claim 5 or claim 6, wherein at least one compartment is under 20 vacuum.

8. A device as claimed in any preceding claims wherein the device incorporates alpha numeric characters.

9. A device as claimed in claim 7, wherein at least one other compartment contains a growth medium additive. 25 10. A device as claimed in claim 9, wherein the growth medium additive is a sanitizing agent such as bleach. 170602NZ Psl_2006U23 929 ADC.doc/JWP/ADC

Received at IPONZ on 27 May 2008 -16-

11. A device as claimed in claim 9 or claim 10, wherein the growth medium additive incorporates a dye.

12. A device as claimed in any preceding claim, wherein the device is provided with a stop member to prevent accidental movement of the cap between the first and second position.

13. A device as claimed in claim 12, wherein the stop member may be integral with the device.

14. A device as claimed in claim 12 or claim 13, wherein disengagement of the stop member is through a combined translation and rotational movement. 10 flius tuovemenrpTa" lever about a pivot could first unlock or other ave the stop 15 member allowlmgmovement of the cap between first and second positions tojtaKe place and then continued movement of the lever could actuate this movementAffernatively the cap and container may be prowled with complementary stop members and movement of one relative to the other may be required to allow subsequent movement of first and second members More preferably the cap and cpntfiiner are provided with complementary stop members to prevent accidental movejn^M of the cap between thefiret and second position: More preferably still movement of the cap relative to\the container in a direction substantially oblique or orthogonal to the line of travel betweenfq-st and second positions is 20 firstrequired to disengage said respective stop members. END OF CLAIM: 25 170602NZ_PsI _20061123_ 929_ADC.doc/JWP/ADC