BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to micropipettes, and particularly those adapted to simultaneously aspirate and dispense multiple aliquots of fluid. Such micropipettes typically utilise disposable pipette tips, into which the fluid is aspirated and thereafter dispensed. The present invention provides a heating arrangement for a micropipette tip array.

Discussion of the Related Art

[0002] Volumetric transfer of fluid in a laboratory setting often involves the simultaneous aspiration and dispensing of multiple aliquots of fluid from a bulk fluid source to a destination such as a multiwell plate (e.g., 96-well plate) or the like, via a plurality of pipettes arranged in an array (e.g., a 96 pipette tip array). Typically, this involves the use of a multichannel micropipette apparatus (multichannel micropipette) which utilise detachable pipette tips, into which the fluid is aspirated and thereafter dispensed, adapted for the simultaneous aspiration and dispensing of multiple fluid aliquots. In some cases, the fluid to be aspirated and dispensed may be in a molten state, where, if the fluid is not immediately transferred from the bulk fluid source to the destination (eg 96-well plate), it will cool in the pipette tips and begin to solidify. For instance, liquid agar preparations (widely used as bacterial growth media) are typically prepared and held at a temperature just above solidification temperature. When the preparation is aspirated in to a pipette tip it immediately starts to cool, and if not transferred quickly enough, will begin to solidify in the pipette tip, leading to wastage of the agar preparation and inadequate dispensing of the agar preparation into the wells of the multiwell plate.

[0003] While solutions exist for individually heating pipette tips to maintain and/or control the temperature of each tip, it will be appreciated that such solutions would be expensive and complex when used in larger arrays (such as 96 pipette tip arrays), and do not lend themselves to scenarios where disposable tips are required.

[0004] It is against this background that the present disclosure is provided. SUMMARY OF THE INVENTION

[0005] A heating arrangement for simultaneously heating a plurality of pipette tips, said heating arrangement comprising: a thermally conductive heating block comprising a plurality of heating chambers, wherein each chamber is in the form of a through opening, the through opening comprising a pipette tip inlet, and a through bore, at least a portion of which tapers inwardly towards the centre of the through opening as it extends through the block from the pipette tip inlet, so as to accommodate a pipette tip or portion thereof, wherein the heating block is configured to be heated so as to simultaneously heat each of the heating chambers and therefore a plurality of pipette tips.

[0006] The heating arrangement may further comprise a heating apparatus such as an electric heating plate or thermoelectric module configured to heat the heating block. In some embodiments, the heating apparatus is configured to maintain the temperature of the heating chambers at a set temperature, such as for example, at 50-55 degrees Celsius (“C”), at 60-65 degrees C, at 65-70 degrees C, at 70-80 degrees C, at 80- 90 degrees C and at 90-95 degrees C. The set temperature enables for example agar preparations contained within pipette tips present in the heating chambers to be maintained in a liquid form and therefore able to be dispensed from the pipette tips. The following table illustrates different temperatures that the heating element could be set for different type of biological reactions:

[0007] In alternative embodiments, the heating element can be set to different temperatures. For example, a portion of the heating element could be set at 55 degrees C while a different portion of the heating element would be set at 80 degrees C. Similarly, the heating element could be set at three, four, or at least five different temperatures.

[0008] The heating arrangement may further comprise an insert configured to locate over the top of the heating block, the insert comprising a plurality of indentations, each configured to locate within a respective heating chamber in the heating block, wherein each indentation is configured to accommodate a pipette tip or portion thereof. Moreover, the heating element can be heated using different techniques such as, but not limited to convection (e.g., air) and/or different conduction heating approaches.

BRIEF DESCRIPTION OF THE FIGURES

[0009] Embodiments of the present invention will be discussed with reference to the accompanying figures wherein:

[0010] Figure 1 is a perspective view of a pipetting system, according to an embodiment;

[0011] Figure 2 is a perspective view of a heating block, according to an embodiment;

[0012] Figure 3 is a cross-sectional view of a portion of the heating block of Figure [0013] Figure 4 is a cross-sectional view of a portion of the heating block of Figure 2, accommodating a pipette tip;

[0014] Figure 5 is a cross-sectional view of a portion of a heating block, according to an alternate embodiment;

[0015] Figure 6 is a perspective view of an insert for a heating block, according to an embodiment; and

[0016] Figure 7 is a cross-sectional view of a portion of the insert of Figure 6 located over the heating block, the insert accommodating a pipette tip.

DETAILED DESCRIPTION

I. Definitions

[0017] The following definitions are provided for specific terms which are used in the following written description.

[0018] As used in the specification and claims, the singular form "a", "an" and "the", include plural references unless the context clearly dictates otherwise.

[0019] The present invention can "comprise" (open ended) or "consist essentially of’ the components of the present invention as well as other elements described herein. As used herein, "comprising" means the elements recited, or their equivalent in structure or function, plus any other element or elements which are not recited. The terms "having" and "including" are also to be construed as open ended unless the context suggests otherwise. As used herein, "consisting essentially of means that the invention may include elements in addition to those recited, but only if the additional elements do not materially alter the basic and novel characteristics of the invention.

[0020] Where a range of values is provided, it is understood that each intervening value, between the upper and lower limits of that range and any other stated or intervening value in that stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

[0021] Terms such as "about," "generally," "substantially," "approximately" and the like are to be construed as modifying a term or value such that it is not an absolute, but does not read on the prior art. Such terms will be defined by the circumstances and the terms that they modify as those terms are understood by those skilled in the art. This includes, at very least, the degree of expected experimental error, technique error and instrument error for a given technique used to measure a value.

[0022] Where used herein, the term "and/or" when used in a list of two or more items means that any one of the listed characteristics can be present, or any combination of two or more of the listed characteristics can be present. For example, if a composition of the present invention is described as containing characteristics A, B, and/or C, the composition can contain A feature alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

Embodiments of the Invention

[0023] Referring now to Figures 2 to 4, there is shown a heating arrangement 1 for heating a plurality of pipette tips. The heating arrangement 1 comprising a thermally conductive heating block 10 comprising a plurality of heating chambers 11, wherein each is in the form of a through opening, the through opening comprising a pipette tip inlet 12, and a through bore 13, at least a portion of which tapers inwardly towards the centre of the through opening as it extends through the block 10 from the pipette tip inlet 12 so as to accommodate a pipette tip or portion thereof, wherein the heating block 10 is configured to be heated so as to simultaneously heat each of the heating chambers 11 and therefore the plurality of pipette tips. [0024] The heating block 10 may be manufactured from a thermally conductive material, such as an aluminium or steel alloy.

[0025] The heating arrangement 1 also comprises a heating apparatus configured to heat the heating block 10. In one form, the heating apparatus is in the form of conventional electric heating plate (not shown), where the heating block 10 sits on top of the heating plate, where by virtue of the conductivity of the heating block 10, the heating chambers within the heating block 10 are heated.

[0026] In another form, the heating apparatus may be in the form of one or more thermoelectric modules, also known as Peltier modules, capable of performing warming and cooling operations.

[0027] The heating arrangement is intended to be used as part of a pipetting system 100, a version of which is shown in Figure 1. The example pipetting system 100 shown comprises a pipette head 110, particularly a multichannel micropipette, configured to aspirate and dispense liquid via a plurality of detachable pipette tips 120. The system also comprises a number of stations. The first station 130 may be used to accommodate a tip rack or basket 131, where the pipette tips 120 are provided in an array and are selectively attached or detached from the pipette head 110. The second station 140 may be used to accommodate a liquid reservoir 141, in which the pipette tips 120 are lowered within to aspirate the liquid held in the reservoir into the pipette tips 120. The third station 150 may be used to accommodate sample plates or racks (for example, a multiwell plate 151) toward which the pipette tips 120 are lowered to dispense the liquid held within the pipette tips 120. It is envisaged that a fourth station 160 may be used to accommodate the heating arrangement 1, where the pipette tips 120 are lowered within the heating chambers 11 in order to be heated, as will be described in further detail below.

[0028] As shown in Figure 2, it can be seen that the heating chambers 21 are arranged in a horizontal two-dimensional 8x12 array so as to accommodate a conventional array of 96 pipette tips. It will however be appreciated that the number of heating chambers and their arrangement may vary in order to accommodate varying pipette arrays. Indeed, it will be appreciated that the 8x12 array is particularly compatible for use with multichannel micropipettes provided with 8, 16, 48 and 64 channels. As would be appreciated, the larger the number of multichannel micropipettes that can be used, the more varied the temperature can be set across the heating element as a whole.

[0029] Referring now to Figure 3, where a cross section of a portion of the heating block 10 is shown, detailing one of the heating chambers 21, it can be seen that the pipette tip inlet 22 has a constant diameter and extends a portion of the way through the heating block, where it then transitions to a tapered portion 24. It will be appreciated that the size and shape of the pipette tip inlet 22 and tapered portion 24 are such that they accommodate a pipette tip to the extent that the length of the pipette tip used to hold liquid is able to be accommodated within the heating chamber 21, as shown in Figure 4.

[0030] It can be seen that the remainder of the through bore 23 below the tapered portion 24 is of constant diameter. The purpose of which will be described in further detail below.

[0031] While in the embodiment shown and described, the heating chambers 21 are sized and shaped to accommodate a particular pipette tip’s shape and size, it will be appreciated that a variety of different sized and shaped heating chambers configured to accommodate a variety of pipette tip shapes and sizes are also intended to fall within the scope of this disclosure. For example, a cross-sectional view of a heating block 20, according to an alternate embodiment is shown in Figure 5, where it can be seen that an edge 25 of the heating block 20 surrounding the pipette tip inlet 22 apers inwardly towards the centre of the through opening as it extends from the pipette tip inlet 22 to the tapered portion 24.

[0032] It is envisaged that the heating arrangement 1 may be incorporated in to an aspirating and dispensing operation in a number of different ways. In one embodiment, the heating apparatus 1 may be used to warm a liquid after aspiration until ready for dispensing. In this arrangement, the pipette head 110 would lift the pipette tips 120 from a tip rack 131, the pipette head 110 would then be positioned above the reservoir 141, where the pipette tips 120 are then lowered in to the liquid held in the reservoir 141, and a desired volume of liquid is then aspirated into the pipette tips 120. The pipette tips 120 are then raised and the pipette head 110 is then positioned above the heating arrangement 1, where the pipette tips 120 are then lowered in to their respective heating chambers 11, keeping the liquid in the pipette tips 120 above a predetermined temperature until ready to be dispensed, at which time the pipette tips 120 will be raised and the pipette head 110 positioned above well plates 151 where the pipette tips 120 will be lowered and the liquid dispensed in to respective wells in the well plate 151. In one example, the liquid may be an agar solution, having a solidification temperature of around 55 degrees C, therefore the heating chambers 11 would be maintained at a temperature beyond 55 degrees C, so as to maintain the solution in liquid form.

[0033] In an alternate embodiment, the heating arrangement 1 may be used to pre-warm the pipette tips 120 prior to aspiration, such that the liquid will not cool as rapidly. In this arrangement, the pipette head 110 would lift the pipette tips 120 from a tip rack 131, the pipette head 110 would then be positioned above the heating arrangement 1, where the pipette tips 120 are then lowered in to their respective heating chambers 11, pre-heating the pipette tips to a predetermined temperature. The pipette tips 120 are then raised and the pipette head 110 positioned above the reservoir 141, where the pipette tips 120 are then lowered in to the liquid, and a desired volume of liquid is then aspirated in to the pipette tips 120. The pipette tips 120 will then be raised and the pipette head 110 positioned above the well plate 151 where the pipette tips 120 will be lowered and the liquid dispensed in to respective wells in the well plate 151. In the same agar solution example described above, the heating chambers 11 would also be maintained at a temperature above 55 degrees C.

[0034] In an alternate method of use, the heating arrangement 1 may be used to carry out, for example, a nucleic acid amplification process such as polymerase chain reaction (PCR) within the pipette tips. In this arrangement, the pipette head 110 would lift the pipette tips 120 from a tip rack 131, the pipette head 110 would then be positioned above the reservoir (which may in this case be standard, single use, sample tube capable of receiving a pipette tip such as a microcentrifuge tube with a 1.5 mL volume (eg Eppendorf Tubes®; Eppendorf, Hamburg, Germany)) containing, for example, a liquid comprising the components required for amplification of a desired nucleic acid molecule/sequence (eg a nucleic acid molecule(s) comprising a sequence to be amplified in combination with a PCR or RT-PCR master mix as are well known to those skilled in the art), where the pipette tips 120 are then lowered in to the liquid, and a desired volume of liquid is then aspirated in to the pipette tips 120. The pipette tips 120 are then raised and the pipette head 110 is then positioned above the heating arrangement 1, where the pipette tips 120 are then lowered in to their respective heating chambers 11, wherein a programmable control arrangement in communication with the heating arrangement 1 cycles the temperature of the heating chambers 11 in order to carry out nucleic acid amplification reactions within the pipette tips 120.

[0035] It will be appreciated that in certain uses, the same pipette tips 120 may be used on a number of occasions, for instance, if a bulk solution is to be dispensed across a plurality of well plates 151 (eg two or more 96-well plates), the same pipette tips 120 may be used for the entire operation. If the heating arrangement 1 is used during and/or between aspiration and dispensing operations, it will be appreciated that an amount of solution carried on the outside of the pipette tips 120 may be transferred to the heating chambers 11. In order to prevent or at least reduce this solution building up and potentially contaminating the pipette tips 120 during subsequent operations, the remainder of the through bore 13 below the tapered portion 14 of each heating chamber 11 encourages drainage of the residual solution. It is envisaged that the through opening may also be coated with a hydrophobic material, be provided with a polished finish, or otherwise treated in such a way to further promote drainage of residue.

[0036] It will be appreciated that the heating block 10 will also be capable of being cleaned and/or rinsed, with the through bore 13 enabling draining of cleaning and/or rinsing solutions. The heating arrangement 1 may also be capable of performing a selfcleaning cycle, where the heating apparatus may be used to increase the temperature of the heating chambers 11 beyond 100 degrees C.

[0037] Referring now to Figure 6, where an insert 30 configured to locate over the top of the heating block 10 is shown. The insert 30 comprises a plurality of indentations 31, each configured to locate within a respecting heating chamber 11 in the heating block 10, wherein each indentation 31 is configured to accommodate a pipette tip 120 or portion thereof, as shown in Figure 7. It will be appreciated that use of the insert 30 still allows for heat transfer from the heating chambers 11 to their respective pipette tips 120 to occur, but without residual from the pipette tips 120 directly contaminating the heating block 10.

[0038] The insert 30 may be manufactured from a thermoplastic, such as polyethylene, polyvinyl chloride, polycarbonate or polyethylene terephthalate, using a vacuum forming process.

[0039] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

[0040] It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the invention is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.

[0041] Please note that the following claims are provisional claims only, and are provided as examples of possible claims and are not intended to limit the scope of what may be claimed in any future patent applications based on the present application. Integers may be added to or omitted from the example claims at a later date so as to further define or re-define the invention.