Vortexing liquid container

Abstract: A nutatable plastic vessel, having a protuberant tip at its bottom end, has its side wall connected by a plastic hinge to a housing.

Description: The present invention relates to a container that facilitates the noninvasive mixing of fluids. It is known that creating a vortex in the fluid contained in a vessel or compartment is an effective means for mixing the contents of the vessel. Common laboratory vortexers use a support cup or a resilient vessel receiving surface mounted eccentrically on a motor in order to translate the loner part of a vessel in a circular path or orbit at a high speed and thereby create an effective vortex in the fluid contained in the vessel. Exemplary of this type of device are those disclosed in US-A-4,555,183 and US-A-3,850,580. These devices are manual in that an operator is required to hold the vessel in contact with the eccentrically movable means to create the vortex in the fluid disposed in the vessel. Such vortex type mixer would be extremely advantageous in an automated chemical analysis instrument as it is noninvasive and therefore avoids the concern of contamination associated with an improperly cleaned invasive mixing means. Unfortunately, when the bottom of a vessel or compartment is orbited to create a vortex, it is difficult to maintain the vessel's lid structure sealed. This is particularly true when there are multicompartments and one is orbited while the remainder remain stationary. Often some of the reagents held in the various compartments are in the form of tabletted reagents which must be hydrated. It is known to utilize ultrasonic energy to facilitate the hydration or dissolving process. One such sonication technique is described in US-A-4,720,374. While entirely a satisfactory procedure, the application of ultrasonic energy is somewhat costly. It is desirable in such automated chemical analyzers to store several reagents in contiguous common reagent vessels. Such a common multivessel container is sold today in an instrument known as the Dimension Chemical Analyzers by E. I. du Pont de Nemours and Company, Wilmington, Delaware. Such strip is described in US-A-4 720 374. This common container is in the form of a container strip which includes a rigid peripheral band formed of an inert plastic. The band is either joined to or formed integrally with each of the vessels such that the container strip generally tapers in a substantially elongated wedge-like manner from a first edge to a second edge. The wedge-shaped plan profile for the container strip facilitates the mounting of a plurality of such strips in a circumferentially adjacent, generally radially extending relationship across a rotatable reagent carrying plate. The tops of the vessels are sealed with a suitable laminate that prevents gas and vapor escape and yet permits penetration by a probe for aspiration, etc. The plastic used for the Dimension™ receptacle is polyethylene and the laminate is a three-ply laminate of a polyester film, a polyvinylidene coating on the polyester film, and finally a sheet of polyethylene which is adhered to the coating. The laminate is sealed to the peripheral surface of the polyethylene vessels with the polyethylene sheet contacting the vessel rims. These prior art containers do not facilitate vortex mixing of only one of the several vessels comprised by the container. When storing a liquid reagent or specimen, care must be exercised to minimize evaporation. Simultaneously, however, whatever structure is used to inhibit evaporation must be compatible with the requirements of access to the liquid as by an aspirating probe during use. US-A-4 720 374 describes such a lid which reduces air and vapor transmission through the top of the lid. By isolating the vessels and thereby forming multivessel containers, contamination between vessels is also reduced. The lid structure described by US-A-4 720 374 is formed of conjoined upper and lower sheets of material. One of the sheets has a receptacle formed therein which receives an elastomeric self-healing pad. A portion of the conjoined first and second sheets forms a sealing flange which completely surrounds the periphery of the receptacle and which provides a surface whereby the lid may be secured by the container. It is the object of the invention to provide a container that facilitates noninvasive mixing of fluids. This object is solved, according to the invention, with the features of claim 1. Many of the problems of automatically mixing materials in the prior art reagent containers are solved by forming a vortexing vessel whose top portion is flexibly held and whose bottom portion is permitted to be nutated about the axis of the vortexing vessel to establish vortex mixing therein. Preferably the plastic used to form the compartment is polypropylene since this provides a flexible hinge having a relatively long life. The laminate, providing the gas and vapor seal, is a three-ply laminate of a polyester film, a polyvinylidene coating on the polyester film, and a sheet of the polypropylene adhered to the coating, the laminate being heat sealed to the peripheral surface with the polypropylene sheet connected to the surface. The hinge is positioned below the mounting surface so that it does not interfere with the nutational movement of the vortexing vessel and so that its mechanical properties are not altered by the lid heat sealing process. The vortexing vessel defines a protuberant bottom tip portion lying along the longitudinal axis. This facilitates engaging the bottom of the vortexing vessel for nutational movement. The housing, which may support additional vessels, as well as the nutational elongated vortexing vessel, has a peripheral mounting surface. Both mounting surfaces lie in the same plane and the laminate is connected to both mounting surfaces but is slit in the region immediately surrounding the rim of the vortexing vessel. This facilitates the nutation of the vortexing vessel's lower end and helps to prevent such nutational movement from disturbing the seal at the peripheral surface of the vortexing vessel. The invention may be more fully understood from the following detailed description thereof taken in connection with the accompanying drawings which form a part of this application and in which similar reference numbers refer to similar elements in all figures of the drawings in which: Figure 1 is an exploded view of the container that is useful for carrying liquids for chemical testing in which each compartment is capable of holding reagents in either liquid or lyophilized (tabletted) form; Figure 2 is a side elevation view of the container of Fig. 1; Figure 3 is a plan view of the multicontainer strip depicted in Fig. 1; and Figure 4 is a cross-sectional side elevational view of the container taken through the sectional line 4-4 of Fig. 3. As may be seen in Fig. 1 a plurality of vessels 10 and a vortexing vessel 13 are arranged in an end-to-end relationship to form a strip-shaped container generally indicated by the reference character 12. The container 12 may be fabricated in any convenient manner. In the embodiment shown, the container 12 includes a rigid peripheral band 14 formed of a suitable material such as an inert plastic. The band 14 is either joined to or preferably is formed integrally with each of the vessels 10 and the vortexing container 13 such that in the preferred case the container 12 generally tapers in a substantially elongated wedge-like manner from a first edge 16L to a second edge 16R. This wedge-shaped plan profile for the container 12 facilitates the mounting of a plurality of such strip-shaped containers 12 in a circumferentially adjacent, generally radially extending relationship across a rotatable reagent carrying plate. A plate of this type described in copending application entitled "Method and Apparatus for Effecting the Automatic Analytical Testing of Samples" (US-A-5 194 808). It should be appreciated however that the individual containers 12 may take any predetermined configuration and may be used alone or arranged together in any convenient number and in any convenient manner and remain within the contemplation of this invention. As is described in US-A-4 720 374, each of the vessels 10 and the vortexing vessel 13 can either be arranged singularly or in a strip-shaped container 12 and is formed of a suitable inert plastic material and includes a compartment defined by generally opposed pairs of generally parallel and integrally formed side walls 18 and endwalls 20. The upper surfaces of the side walls 18 and the endwalls 20 together with the upper surface of the band 14 and the vicinity thereof register to define a substantially planar sealing surface 22 peripherally surrounding the open upper end of the vessel 10 and the vortexing vessel 13. In accordance with this invention, one of the vessels 10, 13 is a vortexing vessel 13. Each of the vessels 10 except for this vortexing vessel 13 is closed by a downwardly sloping inverted paramidal floor 24. The side walls 18 of each vessel 10 except for the vortexing vessel 13 are joined to the peripheral band 14. The band 14 extends slightly below the lower ends of the vessels 10 and thus defines a support structure 26 whereby the container 12 be set on a suitable work surface. The several vessels 10 may be arranged in various configurations square, rectangle, etc. Each of the adjacent vessels 10 and the vortexing vessel 13 are spaced from each other by a predetermined gap 28 to enhance the thermal and vapor isolation of each of the vessels 10 and the vortexing vessel 13. Preferably the container 12 is formed by injection molding and is formed of polypropylene. Alternatively polyethylene or other suitable materials of construction may be used however polypropylene is preferred because of its ability to be flexed many times and not break. In accordance with this invention, the end or vortexing vessel 13 is tubular and elongated and has a longitudinal axis 50. The vortexing vessel 13 also has a rim 52 which defines a peripheral mounting surface similar to the peripheral mounting surfaces provided by the vessels 10 and the band 14. The vortexing vessel 13 is connected to the band 14 by an integral, flexible thin finger of plastic thus forming a flexible hinge 54. The flexible hinge 54 is directed to a corner 56 formed by the band 14 and the end vessel 18. The hinge 54 is located just below the rim 52 such that it does not interfere the vapor seal which is placed on top of the vortexing vessel 13 and the vessels 10 and so that its mechanical properties are not affected by the lid heat sealing process. The bottom of the vortexing vessel 13 is formed to have a downwardly extending protuberant tip portion 58 which is adapted to being engaged by an eccentric or orbiting type drive to create nutational movement of its bottom portion, the vortexing vessel 13 pivoting about the flexible hinge 54. The lower portion of the band 14 is removed to form a short skirt about the vortexing vessel 13 such that the vortexing vessels 13 is free for such nutational movement at its lower portion. A suitable drive for the protuberant tip portion 58 to provide such nutational motion is described in copending application U.S. Serial No. 07/237,254 and entitled "Automatic Vortex Mixer" . An alternative drive that may be used is that described in an article by Wada et al., Automatic DNA Sequencer: Computer-programmed microchemical manipulator for the Maxam-Gilbert sequencing method. Rev. Sci. Instrum., 54 (11), 1969-72. Since the particular drive does not form a part of this invention, it will not be described further except to say that the function of the drive is to engage the protuberant tip and move it in an nutational, or orbital type movement so as to establish vortex mixing within the vortexing vessel 13. When reagents are stored in the vessels 10 and in the vortexing vessel 13 it is best that a vapor barrier and a rehealable sheet be used to afford plural piercings by a probe for withdrawal of the reagent. For this reason, a three-ply laminate 60 is heat-sealed to the peripheral mounting surfaces of the vessels 10 as well as the vortexing vessel 13 and the band 14 particularly where it forms a skirt about the rim 52 of the vortexing vessel 13. To facilitate sealing of the individual compartments, a small notch 64 is formed in the molding process between each vessel 10 but for the vessel 10 adjacent the vortexing vessel 13. Finally, a self-healing lid structure 66 is adhered to the laminate 60. The self-healing structure 66 may be any of the elastomers that are chemically inert. It is preferred however that a silicon rubber sheet, having a thickness of 0,813 mm (32 mils), sold by CHR Industries be used. It is applied to the laminate 60 with a suitable adhesive such as that as available from the General Electric Company of Waterford, NY having a product identification of TSA6574 which is a silicone resin which uses a primer solution having a product identification of SR500. The end of the lid structure 66 which is over the vortexing vessel 13 has its exterior cutaway forming a semicircular end having the same diameter and width as that of the vortexing vessel 13. Further, the laminate 60 is slit immediately about the rim 52, prior to application of the lid structure 66, to facilitate the nutational movement of the container 12 without disturbing the seals. The laminate closes each of the vessels 10,13 with an impermeable seal so as to form an evaporation barrier for the contents of the vortexing vessel 13 and the vessel 10 and to isolate the compartment and vessels 10,13 against vapor cross contamination and isolate the vessels 10,13 from contaminating gasses such as carbon dioxide or oxygen. Since the laminate 60 is heat sealed to the mounting surfaces surrounding each vessel 10, the rim 52 of the vortexing vessel 13, and the container 12 the material of the lower ply must be heat sealable to the plastic forming the band 14. In its preferred embodiment the laminate 60 is three-ply laminate with the outer layer a polyester film such as that sold by E. I. du Pont de Nemours and Company under the trademark Mylar®, a polyvinylidene chloride coating on the polyester film such as that sold by Dow Chemical Co. under the trademark Saran®, and finally an outer barrier sheet of polypropylene since the band 14 is made of polypropylene. If the band 14 were made of polyethylene this lower laminate would be polyethylene. The lid structure 66 may be provided with slits to facilitate the insertion of probes into the vortexing vessel 13 and vessels 10. The use of the silicon rubber, which is a self-healing elastomer, provides a wiping action on the probe, does not tend to stick to the probe, is not easily cored. The seal is not disturbed by the nutational movement of the vortexing vessel 13. Such nutational movement is particularly facilitated by the slitting of the laminate about the top rim 52 of the vortexing vessel 13. The flexible hinge 54 has a relatively long life and hence permits significant nutational movement of the vortexing vessel 13.

Claims: A container (12) having a housing for a nutational elongated vortexing vessel (13) having a side wall and a longitudinal axis (50), the vortexing vessel (13) being of plastic material and having a peripheral mounting surface (52), said housing having a peripheral mounting surface lying in the same plane with the mounting surface (52) of the vortexing vessel (13), the housing comprising: a flexible hinge (54) connecting the housing to a side wall of the vortexing vessel (13) and being integral with both the housing and vortexing vessel (13), said flexible hinge (54) being positioned below the mounting surface of the vortexing vessel, a laminate (60), providing a gas and vapor seal and being connected to the mounting surface (52) of the vortexing vessel, the laminate (60) also being connected to the housing peripheral mounting surface and being slit (74) in the region immediately surrounding the vortexing vessel (13), thereby to facilitate nutation of the lower end of the vortexing vessel (13). A container as set forth in claim 1 wherein the vortexing vessel (13) is of polypropylene and the laminate (60) is of a three ply laminate of a polyester film, a polyvinylidene coating on the polyester film, and a sheet of the polypropylene adhered to the coating, the laminate (60) being sealed to the peripheral mounting surfaces with the polypropylene sheet connected to the mounting surfaces. A container as set forth in claim 1 or 2 wherein the housing surrounds the vortexing vessel (13) about the upper portion of the side walls coaxially to the longitudinal axis (50) leaving the vortexing vessel (13) lower portion easily accessible. A container as set forth in one of claims 1-3 wherein the vortexing vessel (13) defines a protuberant tip portion (58) lying on the longitudinal axis (50) and extending downwardly from the vortexing vessel (13). A container as set forth in one of the claims 1-4 wherein the housing also defines a vessel (10) having a peripheral mounting surface lying in the said same plane, the vessel (10) being located contiguous the vortexing vessel (13), the laminate (60) also being connected to the peripheral mounting surface of the vessel.

Inventors: BENIN JOSHUA, DI MAIO WILLIAM G, LAWLER JAMES A, MORIN CARL F, BENIN, JOSHUA, DI MAIO, WILLIAM G., LAWLER, JAMES A., MORIN, CARL F.
Applicants: DU PONT, E.I. DU PONT DE NEMOURS AND COMPANY
Application year: 1989
Main classification: B01F11
IPC codes: B01F15, G01N1, B01F11