TECHNICAL FIELD

The scope of the present invention (1) has its focus on the reduction of laboratory steps, reducing processing time, minimizing errors, decreasing laboratory materials consumption and, therefore, minimizing the costs on laboratory procedures where the currently available pipette tips and centrifuge tubes are normally used. Thus, the optimization of the pipetting and storage process is aimed by combining the functions of these two laboratory consumables through the design of an innovative pipette tip (2) and its tight lid (9) . The reduction of the drawbacks listed before are obvious, particularly, observing the present invention (1) ability of pipetting a determined liquid volume and to ensure tightness of the content by fitting the correspondent lids (6) and (9) . Thus, the present invention (1) stores the liquid content in biological security conditions, maintaining its physical and chemical integrity, enabling future centrifugation and analysis. BACKGROUND OF THE INVENTION

The dosing of small volumes of fluids for clinical, biological analysis or others is carried out typically using commercial pipettors. These dosing devices use interchangeable pipette tips to avoid contamination when dosing different fluids. These pipette tips have two holes, an upper hole to enable the fitting on the pipettor and the lower hole to enable the entrance of the liquid sucked through vacuum by the pipettor, as the pipette tips described in US4748859, US7320259, US2006/0233669, US2008/0078258 and US2010/0218622.

The storage of the dosed liquid volume can be performed using Eppendorf type test tubes (US5354539, US5254314, US2007/0031297 ) and fluid discharge from the pipette tip to the centrifuge tube is achieved by interrupting the vacuum realized by the pipettor, consequently, the fluid content is ejected to the centrifuge tube. The centrifuge tube is then closed and can proceed to the centrifugation process.

The documents CN201164593 Y and JP2010038876 A are considered the closest solutions concerning the problem to be solved with the present invention (1).

The document CN201164593 Y refers to a pipette tip combined with a centrifuge tube whose main purpose is to prepare platelet rich plasma and its main difference consists on an upper lid with a multifunctional hole that seals simultaneously the centrifuge tube and the pipette tip. Thus, after centrifugation and the consequent fluid stratification, it is possible to extract and analyse the desired volume fraction without having to introduce again the pipette tip inside the centrifuge tube.

The document JP2010038876 A refers to a centrifuge tube which main feature is to have an inside step to enable the pipetting of a lower density fluid, since after the centrifugation procedure, the higher density fluid remains at the bottom of the centrifuge tube.

The present invention (1) differs from the others by having a tight lid (9) and a annular snap-fit (8) that, after fitting, ensure the sealing of the lower hole (4) . Therefore, the present invention (1) shows innovation by combining the functions of a pipette tip and a centrifuge tube, enabling that dosing and storage procedures can be made on the same unit of volume. Thus, the centrifugation process is performed ensuring liquid content tightness, preventing liquid loss and liquid contamination from the outside . BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 - Schematics of invention (1), which besides pipetting, enables storage for future liquid content analysis, by fitting the lids (6) and (9) on the correspondent upper (3) and lower holes (4) . The pipette tip (2) has an upper lid (6) which is connected to the pipette tip (2) through the integral hinge (5), enabling the articulation of the upper lid (6) and the fitting of the upper socket (7) on the upper hole (3) . The geometry of the upper socket (7) ensures liquid content tightness, although it enables successive opening and closing operations. The annular snap-fit (8) on the bottom of the pipette tip (2) enables the fitting of tight lid (9), fully closing the system. The geometries of the annular snap-fit

(8) and the tight lid (9) are designed to ensure that the lower hole (4) is permanently closed. The lower hole (4) has the diameter D5 suitable for a precise and effective pipetting process.

Figure 2 - Section view of the tight pipette tip for centrifuge (1), depicting the inside and outside diameters on the pipette tip (2), respectively Dl and D2. The diameter Dl was designed to fit on the bays of a centrifuge and the diameter D2 was designed to be linked on a pipettor .

Figure 3 - Schematic representation of the fitting between the body of the pipette tip (2) and the tight lid (9) .

Figure 4 - Section view of detail A of Figure 3, showing the fitting between the pipette tip (2) and the tight lid

(9) . This detail illustrates the tight lid (9) assembled on the annular snap-fit (8), whose geometries are designed to ensure full volume sealing by applying the required effort. The depth HI of the tight lid (9) should be higher than the height H2 of the annular snap-fit (8) and the diameter D3 of the annular snap-fit (8) should be lower than the inside diameter D4 of the tight lid (9) to enable assembly. The diameter D6 of the conical pin (11) should be higher than the diameter D5 of the lower hole (4) to ensure liquid tightness Figure5 - Schematical representation of the assembly of the tight lid (9) on the pipette tip (2) and the closing of the upper hole (3) through the upper lid (6) . This representation also shows the useful length H3 and the maximum length H4 of the invention (1). The useful length H3 is suitable for the depth of the centrifuge bays.

Figure 6 - Schematical representation of the pipetting process using the present invention (1) . Figure 6a - Represents the pipette tip (2) fitted on a generical pipettor, sucking a fluid through the lower hole (4) from a generic container.

Figure 6b - Represents the pipette tip (2) with the liquid content dosed within, with the tight lid (9) being placed while the pipettor maintains the vacuum.

Figure 6c - Represents the invention (1), showing the lower hole (4) closed by the tight lid (9) and the upper hole (3) closed by the upper lid (6) . Figure 6d - Illustrates the invention (1) with the fluid content dosed within, placed On a bay of a generic centrifuge .

SUMMARY OF THE INVENTION

The present invention (1) refers to a tight pipette tip for a laboratory centrifuge enabling both pipetting and storage functions, resulting from the combination of the features of two laboratory products currently available, the pipette tip and the centrifuge tube. The present invention (1) has the ability of pipetting the desired liquid volume and after fitting the tight lid (9) through the annular snap-fit (8) on the lower hole (4) and fitting the upper socket (7) on the upper hole (3) through the upper lid (6) which is connected to the centrifuge tip (2) through the integral hinge (5), can be stored or analyzed, maintaining its physical and chemical integrity as well as liquid tightness. Laboratory procedures can then be simplified with the present invention (1) since the pipetted liquid content, storage and analysis can be performed on the same unit of volume. DETAILED DESCRIPTION OF THE INVENTION

The present invention (1) refers on a pipette tip (2) and a tight lid (9) for pipetting and storage functions, resulting from the combination of the features of two laboratory products currently available, the pipette tip and the centrifuge tube. These laboratory consumables, pipette tip and the centrifuge tube, are individually and concomitant used worldwide in research and educational laboratories to perform tests and analysis in domains such as chemistry, molecular biology and biochemistry.

The present invention (1) is focused on the optimization of processes where pipette tips and centrifuge tubes are normally used, by reducing or even eliminating the drawbacks caused by the use of both devices. The use of the present invention (1) avoids contamination resulting from pipetting and storage operations in different volume units, dosing inaccuracy due to the residual fluid volume that remains on the pipette tip, expenditure of consumables that are discarded necessarily after use, minimization of operator errors and shortening operation time.

Since the pipetted liquid volume is defined by the automatic pipettor, it is noticed that the content transfer procedure from the pipette tip to the centrifuge tube proves to be unnecessary, since it possesses the drawbacks described before. The present invention (1) intends to simplify the laboratorial process of pipetting, storage and analysis fluids in the same volume unit.

The present invention (1) consists on a pipette tip (2) and a tight lid (9) . The pipette tip (2) has, on its top side, an upper lid (6) that is connected through an integral hinge (5), which enables the articulation of the tight lid (6) and the fitting of the upper socket (7) on the upper hole (3) . The upper hole (3) diameter is suitable to fit the pipettor, enabling vacuum pipetting to be efficient. The geometry of the upper socket (7) ensures liquid content tightness, although it enables successive opening and closing operations.

Thus, the sealing of the pipetted liquid content is ensured by fitting the tight lid (9), subsequent removal of the pipettor and adjustment of the upper lid (6) , which is connected to the pipette tip (2) through the integral hinge (5) . On the bottom of the pipette tip (2) there is the lower hole (4) with the diameter D5 suitable for a precise and effective pipetting process. Close to the bottom of the pipette tip (2) , there is the annular snap- fit (8) which enables the fitting of the tight lid (9) by applying the required effort, considering that the geometries of the annular snap-fit (8) and tight lid (9) are designed to ensure full volume sealing, since once fitted the lower hole (4) is permanently closed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For the embodiment of the present invention (1) and not restricting its protection scope, it is noted that: a. the manufacturing process to be adopted for the invention (1) is injection moulding of thermoplastics, since it is the mass production technology that enables the processing of a suitable raw material and to reduce the correspondent manufacturing costs;

b. the raw material adopted for the invention (1) could be polypropylene (homopolymer or copolymer) or polydxymethylene, since these are the raw materials that enable the use of the integral hinge (5) . The following dimensional characteristics of the invention (1) are provided only by way of example and are not intended to limit it in any way: c. the diameter D5 may vary between 0,25 and 1.2 mm depending on the viscosity of the fluid to be pipetted;

d. the diameter Dl may vary between 5.85 and 19.28 mm depending on the diameter of the bay of the centrifuge;

e. the diameter D2 may vary between 4.37 and 17.78 mm depending on the size of the pipettor;

f. the length H3 can have up to 43 mm depending on the depth of the bay of the centrifuge, considering that this length can be enlarged to increase the volume capacity of the invention (1) .