PIPETTE TIP DISPOSAL ASSEMBLY

Abstract

There is provided a pipette tip disposal assembly. The assembly comprises a receiving element adapted to support an end of at least one pipette tip, the at least one pipette tip being toppled in use from the receiving element along a first direction; and a container positioned to receive the at least one toppled pipette tip, the at least one pipette tip falling towards a base of the container on being received by the container. The base of the container has a first linear dimension aligned with the first direction corresponding to the length of a pipette tip.

Claims

1. A pipette tip disposal assembly comprising: a receiving element adapted to support an end of at least one pipette tip, the at least one pipette tip being toppled in use from the receiving element along a first direction; and a container positioned to receive the at least one toppled pipette tip, the at least one pipette tip falling towards a base of the container on being received by the container, wherein said base of the container has a first linear dimension aligned with the first direction corresponding to the length of a pipette tip.

2. The pipette tip disposal assembly of claim 1, wherein the receiving element is at a separation of no more than three times the first linear dimension from the base of the container.

3. The pipette tip disposal assembly of claim 1, wherein the receiving element is at a separation of no less than half the first linear dimension from the base of the container.

4. The pipette tip disposal assembly of claim 1, wherein the receiving element comprises a planar portion.

5. The pipette tip disposal assembly of claim 4, wherein the planar portion of the receiving element is at an angle with respect to the horizontal plane.

6. The pipette tip disposal assembly of claim 5, wherein the angle is 2 degrees (°).

7. The pipette tip disposal assembly of claim 1, wherein the receiving element and the container are connected.

8. The pipette tip disposal assembly of claim 7, wherein the receiving element and the container are a single unitary body.

9. The pipette tip disposal assembly of claim 1, wherein a guide feature is formed on the container so as to indicate an orientation of the receiving element.

10. The pipette tip disposal assembly of claim 1, wherein the first linear dimension is no more than 5 millimetres (mm) greater than the length of a pipette tip.

11. The pipette tip disposal assembly of claim 1, wherein the container comprises sides that taper outwardly from the base of the container to an opposing end of the container.

12. (canceled)

13. The pipette tip disposal assembly of claim 1, wherein the base of the container has a second linear dimension corresponding in magnitude to the first linear dimension.

14. A biochemical testing system comprising: a pipette tip disposal assembly comprising: a receiving element adapted to support an end of at least one pipette tip, the at least one pipette tip being toppled in use from the receiving element along a first direction; and a container positioned to receive the at least one toppled pipette tip, the at least one pipette tip falling towards a base of the container on being received by the container, wherein said base of the container has a first linear dimension aligned with the first direction corresponding to the length of a pipette tip, and a delivery mechanism adapted to hold at least one pipette tip in use, wherein the delivery mechanism is configured to deliver the at least one pipette tip to a receiving element of the pipette tip disposal assembly and release the at least one pipette tip so as to cause the at least one pipette tip to topple into the container of the pipette tip disposal assembly.

15. The system of claim 14, wherein when delivering the at least one pipette tip delivery mechanism is further configured to hold the at least one pipette tip at a first separation above the receiving element.

16. The system of claim 14, wherein when releasing the at least one pipette tip, the delivery mechanism is further configured to: position the at least one pipette tip such that an end of the at least one pipette tip is supported by the receiving element, and maintain contact with the at least one pipette tips so as to retain the at least one pipette tip in place on the receiving element.

17. The system of claim 16, wherein releasing the at least one pipette tip further comprises the delivery mechanism applying a force to the at least one pipette tip so as to cause the at least one pipette tip to be toppled along the first direction.

18. The system of claim 14, wherein the delivery mechanism comprises a Cartesian coordinate robot.

19. The system of claim 14, further comprising a recess adapted to accommodate the container.

20. The system of claim 19, wherein the recess is adapted to form interference fit with the container when accommodating the container.

21. The system of claim 19, wherein: a guide feature is formed on the container so as to indicate an orientation of the receiving element; and the recess has an element adapted to cooperate in use with the guide feature to determine an orientation of the receiving element when accommodating the container.

Description

BRIEF DESCRIPTION OF FIGURES

[0025] An example pipette tip disposal assembly will now be described in detail with reference to the following figures:

[0026] FIG. 1 shows a perspective view of a pipette tip disposal assembly according to an example of the present invention.

[0027] FIG. 2 shows a further perspective view of the pipette tip disposal assembly of FIG. 1 along with pipette tips in a supported position.

[0028] FIG. 3 shows an additional perspective view of the pipette tip disposal assembly of FIG. 1, and pipette tips in a toppling position.

[0029] FIG. 4 shows a plan view of a pipette tip disposal assembly with pipette tips held by a container of the assembly.

[0030] FIG. 5 shows a side view of the pipette tip disposal assembly of FIG. 1, with a pipette tip shown inside a container of the assembly.

DETAILED DESCRIPTION

[0031] Some biochemical analysers use disposable pipette tips to hold liquid samples. When such pipette tips have been used and are no longer needed, they are disposed of.

[0032] Typically pipette tips of different lengths can be used. In the example described herein two different lengths are used, and the dimensions of some structural features are described herein in terms of a length of the longer variety by reference to, for example, “the length of a pipette tip”. Pipette tips of the shorter variety have a length approximately half that of the longer variety. In this example, pipette tips of the longer variety have a length of approximately 98 millimetres (mm) and a capacity of approximately 1000 microlitres (μL), and those of the shorter variety have a length of approximately 58 mm and a capacity of approximately 50 μL.

[0033] A pipette tip disposal assembly is generally illustrated at 10 in FIG. 1. The assembly 10 includes a container 11 adapted to hold a plurality of used pipette tips 30 (shown for example in FIG. 2).

[0034] The container 11 has a generally square base 13 whose internal sides are each of a length corresponding to the length of a pipette tip. By this we mean that the length of each internal side is no more than about 10 mm longer than a pipette tip of the longer variety, and the sides in this example are approximately 5 mm longer than the length of the tip. A first linear dimension and a second linear dimension of the base are indicated by the distances a-a and b-b respectively and represent the internal dimensions of the base 13 of the container 11.

[0035] The container has four walls extruding from the base 13 to an opening of the container 11 at an opposite end of the container 11 to the base 13. The walls include a first wall 14, a second wall 15 opposite the first wall 14, and two side walls 16, 17. The walls are upstanding and taper outwardly from the base 13. At the opening there is a rim providing a flanged portion extending laterally outward from three of the walls. The rim is provided for each wall except the second wall 15.

[0036] For the first wall 14, at the opening the flanged portion provides a receiving element in the form of a shelf 12. The shelf 12 is inclined at an angle of 2° to the horizontal (i.e. at 2° to the plane of the base 13). In this example the shelf 12 extends approximately 10 mm from the first wall to the edge of the container.

[0037] The height of the walls, which in this example corresponds approximately to the separation of the shelf 12 and the base 13, is indicated by the distance c-c. In this example, this distance is approximately twice the length of a pipette tip 30. The dimensions given in this example allow the container 11 to hold approximately 384 pipette tips 30 in a hexagonal close-packed arrangement.

[0038] The opening of the container 11 has internal dimensions d-d and e-e, which are each approximately 15 mm greater than the corresponding internal dimensions a-a and b-b of the base 13.

[0039] A projecting guide feature 18 is formed in one side wall 16 of the container. This indicates the orientation of the shelf 12 and assists a user when positioning the assembly 10 for use.

[0040] The walls 14, 15, 16, 17 are formed so as to have two lateral steps 19, 20 each spanning the perimeter of a portion of the walls 14, 15, 16, 17.

[0041] Surrounding the rim of the container 11 is an upstanding wall 20. This wall also extends along the end of the second wall 15 at the opening of the container 11. The upstanding wall 20 is adapted to accommodate a lid (not shown) of dimensions matching those of the area enclosed by the vertical wall 20. Such a lid is able to be used to seal the container after the container has been filled with pipette tips 30, and thereby reduces the possibility of any fluid collected on the inside of the container 11 from contaminating the surrounding environment. The vertical wall 20 also reduces the likelihood of fluid on the shelf 12 from escaping the assembly 10.

[0042] In this example, all of the elements illustrated in, for example, FIG. 1, are formed as a single unitary body, which may is manufactured by an injection moulding technique.

[0043] The pipette tip disposal assembly 10 is arranged to collect pipette tips 30 in a biochemical testing system. In the biochemical testing system, pipette tips 30 are used to hold samples that are delivered to various parts of the system to follow a predetermined assay and then, once used, delivered to the pipette tip disposal assembly 10.

[0044] The biochemical testing system includes an aperture (not shown) adapted to accommodate the pipette tip disposal assembly 10. In this arrangement, an interference fit is formed as the container 11 is urged into the aperture under the influence of gravity. The steps 19, 20 on the sides of the container 11 cause the container 11 to assume a level position. The aperture is formed so as to only permit the container 11 to be inserted at a particular orientation determined by the position of the projecting guide feature 18. This is achieved by one side of the aperture having a recess (not shown) that has a shape complementary to the guide feature 18 of the container. Accordingly, the container only fits into the container when the guide feature and the recess are aligned.

[0045] The biochemical testing system includes a delivery mechanism capable of holding at least one pipette tip 30 and delivering the at least one pipette tip 30 to the pipette tip disposal assembly 10. In the example shown in the figures, the delivery mechanism is capable of holding four pipette tips. This delivery mechanism includes a Cartesian coordinate robot adapted to hold and transport pipette tips 30. Such a robot is capable of moving along three orthogonal axes.

[0046] To dispose of used pipette tips 30 with the pipette tip disposal assembly 10, the robot brings the pipette tips 30 to the assembly and holds the pipette tips 30 in a row at a small separation above the shelf 12. The pipette tips 30 are then released such that the pipette tips 30 drop down and a lower end portion 31 of each of the pipette tips 30 comes into contact with the shelf 12. Due to the separation between the tips 30 and the shelf 12 before the tips are released (typically less than 5 mm), the robot maintains loose contact with an opposing end portion 32 of each of the pipette tips 30. This maintains the pipette tips 30 in a substantially upright position on the shelf 12. FIG. 2 shows this arrangement with four pipette tips 30 supported upright on the shelf 12 by the robot (not shown). Although FIG. 2 shows the pipette tips 30 arranged with a regular spacing between adjacent pipette tips 30, a variety of separations may be used.

[0047] Once the pipette tips 30 have been positioned upright on the shelf 12 by the robot, the robot is moved along a first direction as is indicated by the arrow D in FIG. 1. This applies a lateral force to the pipette tips 30 supported on the shelf 12. Due to the loose contact between the robot and the pipette tips, this causes the ends 32 of the tips in contact with the robot to be moved in the first direction D, thereby pivoting the tips around the ends 31 supported on the shelf. As the tips 30 are pivoted they come out of contact with the robot, thereby completing the release of the tips 30. This in turn causes the pipette tips 30 to topple along the first direction D and fall into the container 11. Once the robot is out of contact with the pipette tips 30, it comes to a stop at a position above the container that is approximately equidistant from the first wall 14 and the second wall 15. In this example, this occurs when the pipette tips are at an angle approximately 45° in relation to the container.

[0048] FIG. 3 illustrates four pipette tips 30 being toppled from the shelf 12 of the assembly 10. At the instant shown in this figure, the pipette tips 30 are out of contact with the robot and are able to fall under the influence of gravity towards the base 13 of the container 11. The speed at which the robot moves is chosen such that the most ordered pattern of stacking is achieved. In this example the robot moves at approximately 100 mm per second (mm/s).

[0049] FIGS. 2 and 3 both illustrate the use of the assembly 10 solely with pipette tips 30 of the longer variety, though as mentioned above the assembly may also be used to collect pipette tips 30 of the shorter variety (not shown). For example, ordered stacking would still be achieved if one of the four pipette tips 30 illustrated were replaced with a pipette tip of the shorter variety. It is of course not necessary to use exactly four pipette tips 30 each time tips are to be disposed of using the assembly. Indeed, the assembly 10 would function correctly with more or fewer tips than this number.

[0050] The pipette tips 30 are caused to fall in such a way that they land approximately parallel to the base 13 of the container 11. This is achieved by limiting the speed at which the tips 30 are toppled by the robot and the depth of the container 11. This minimises the time between the first instant at which each pipette tip 30 collides with the base 13 of the container 11 and that at which the pipette tips 30 ultimately come to rest, thereby reducing the chance of disorder developing as the tips 30 are introduced to the container 11.

[0051] As the pipette tips 30 are pushed along the first direction D by the robot, they begin to rotate. As explained above, it is preferable that the pipette tips land approximately parallel with the base 13 of the container 11, so a rotation of at least approximately 90° is desirable. If, however, the rate at which the pipette tips 30 are rotating as they collide with the base 11 is too great, then the pipette tips 30 may rebound in such a way that can introduce disorder into the pattern of stacking. As mentioned above, it is preferable that the force applied by the robot is sufficient only to cause the minimum rotation necessary to cause the pipette tips 30 to fall flat onto the base 13, i.e. approximately 90° only.

[0052] The first linear dimension of the base 13 is closely matched to the length of the pipette tips 30. This means that movement of pipette tips 30 that land on the base 13 approximately parallel to the first direction D will be restricted by the first wall 14 and the second wall 15 of the container, thereby preserving the alignment of the tips 30 on the base 13. This allows a first ordered layer of pipette tips 30 to be formed on the base 13. Once a first ordered layer of pipette tips 30 has been formed on the base 13 of the container 11, subsequently introduced pipette tips 30 will typically to come to rest in the gaps between those pipette tips 30 already in the container because they will naturally adopt a close-packed arrangement due to the uniformity of the tips and the consistent alignment. In this way, an ordered stack of pipette tips 30 is formed as successive groups of tips are toppled into the container 11.

[0053] FIG. 4 illustrates a plan view of the assembly 10 after four pipette tips 30 have been toppled from the shelf 12 and have landed on the base 13 in an ordered arrangement. The first end portions 31 of the pipette tips that were in contact with the shelf 12 are facing the first wall 14 and the opposing ends 32 of the pipette tips are facing the second wall 15. FIG. 5 shows a side view of this, showing the pipette tips 30 located on the base of the container on their sides.