Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
  • G01F23/0053—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm with over-flow pipes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
  • B01L3/02—Burettes; Pipettes
  • B01L3/0289—Apparatus for withdrawing or distributing predetermined quantities of fluid
  • B01L3/0293—Apparatus for withdrawing or distributing predetermined quantities of fluid for liquids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
  • B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
  • B01L3/502—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2200/00—Solutions for specific problems relating to chemical or physical laboratory apparatus
  • B01L2200/06—Fluid handling related problems
  • B01L2200/0605—Metering of fluids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2200/00—Solutions for specific problems relating to chemical or physical laboratory apparatus
  • B01L2200/06—Fluid handling related problems
  • B01L2200/0642—Filling fluids into wells by specific techniques
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0832—Geometry, shape and general structure cylindrical, tube shaped
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2300/00—Additional constructional details
  • B01L2300/08—Geometry, shape and general structure
  • B01L2300/0861—Configuration of multiple channels and/or chambers in a single devices
  • B01L2300/087—Multiple sequential chambers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L2400/00—Moving or stopping fluids
  • B01L2400/04—Moving fluids with specific forces or mechanical means
  • B01L2400/0403—Moving fluids with specific forces or mechanical means specific forces
  • B01L2400/0406—Moving fluids with specific forces or mechanical means specific forces capillary forces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
  • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
  • B01L3/50—Containers for the purpose of retaining a material to be analysed, e.g. test tubes
  • B01L3/502—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures
  • B01L3/5027—Containers for the purpose of retaining a material to be analysed, e.g. test tubes with fluid transport, e.g. in multi-compartment structures by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip

Definitions

• This invention relates to new and improved apparatus and method for the self-levelling of a liquid in a container to a precisely predetermined level with a concave liquid meniscus, and includes new and improved apparatus and metnod to insure that such liquid is completely bubble-free; all particularly adapted to use in contemporary, highly accurate automated sample liquid analysis systems.
• a separate liquid level adjusting device in addition to the standard liquid container is required, and must be operatively inserted into the latter to pump the liquid tnerefrom into the device to overfill the same back into the container, tnus leaving the liquid in the device at a predetermined level relative to the container and coincident with the capacity of the liquid level adjusting device; while in 4,758,409 direct overfilling of the microsample cup, wnich can be somewhat difficult due to the extremely small size thereof, is required.
• United States Patents 4,602,995 and 4,758,409 are, in any event, totally devoid of any disclosure of the utilization of capillary action in the self-levelling of a liquid in a container.
• This patent does clearly disclose the provision of a concave meniscus on the reagent liquid in the dispensing well, and the central positioning thereon of a precisely predetermined volume or "lens" of an appropriate immiscible isolation liquid for sample liquid carryover minimization purposes.
• United States Patent 4,515,753 and 4,774,057 are again, in any event, totally devoid of the utilization of capillary action in the self-levelling of a liquid in a container.
• debubblers function to debubble a sample liquid stream, which had previously been pruposefully air-segmented for sample liquid carryover minimization purposes as has now long been standard in the automated successive sample liquid analysis art, prior to sample liquid introduction to the actual analysis means so as not to adversely affect the accuracy of the analysis results; and, as such, would clearly have no applicability to the introduction of a completely bubble- free liquid to a container attendant the "filling" thereof. Too, it is not certain that prior art debubblers of this nature would be fully effective to totally remove extremely small air bubblers as may be entrained within the sample liquid, as opposed to inter sample liquid segment air segments.
• the invention comprises new and improve apparatus and method for the self-levelling of a liquid in a container to a precisely predetermined level, with a concave meniscus; and, as representatively disclosed herein, takes the form of one or more ribs which form sharp-cornered surface junctures with the container surfaces, and which extend contiguously from the predetermined liquid level within the container at the interior container wall upwardly and across the upper container edge or lip, and downwardly therefrom along the exterior container wall to a level on the latter which is below the predetermined liquid level in the container.
• These sharp-cornered rib-container surface junctures form contiguous capillary pathways for capillary liquid flow which are coextensive therewith.
• the container and ribs are fabricated from a material which is readily wettable by the liquid in accordance with the formation by the latter of a contact angle of less than 90° with the former, thereby insuring capillary rise of the liquid in the provided capillary pathways.
• the liquid is conveniently introduced to the container to any practical level above the predetermined level thereby contacting and wetting the relevant portions of the capillary pathways, and this results in the virtually immediate capillary rise of the liquid in those pathways in response to the same to commence liquid flow therein; with the head provided by the difference in levels as described functioning through siphon-like action to continue the same.
• Liquid flow out of the container continues as described in the provided capillary pathways until the level of the liquid in the container falls immediately below the level on the interior container wall at which the sharp-cornered rib container surface junctures, and thus the provided capillary pathways, commence; thereby leaving the liquid in the container at the precisely predetermined level, and with a concave meniscus thereon.
• the invention further comprises new and improved apparatus and method for the completely bubble-free introduction of a liquid from a liquid supply chamber to a container which is not in direct liquid flow communication therewith; and, as representatively disclosed herein, again comprise one or more ribs which form sharp-cornered surface junctures, and thus capillary pathways as heretofore described, with the respective liquid supply chamber and container surfaces; and which, in this instance, extend contiguously from a level in the liquid supply chamber essentially at the bottom thereof upwardly along the interior chamber wall, across the upper edge or lip of a common supply chamber and container wall which divides the same, and downwardly into the container along the interior wall to a level essentially at the container bottom.
• the liquid supply chamber and the container are relatively disposed so that the bottom of the chamber is at a level above the full liquid level of the container.
• the liquid is conveniently introduced to the liquid supply chamber to any practical level commensurate with the liquid requirements of the container, thereby contacting and wetting the capillary pathways in the chamber, and this results in the virtually immediate capillary rise of the liquid in those pathways in response to the same to commence liquid flow from the supply chamber to the container; with the head provided by the difference in levels as described functioning through siphon-like action to continue liquid flow until substantially all of the liquid in the supply chamber has been flowed into the container along the provided capillary pathways. Since gases cannot flow along capillary pathways by capillary action, completely bubble- free liquid, only, will be introduced as described from the liquid supply chamber to the container.
• the invention further comprises the combination of the teachings of the new and improved bubble-free liquid introduction apparatus and method, and the new and improved self-levelling apparatus and method, both as heretofore described; and, as representatively disclosed herein takes the form of a unitary container assembly which includes a liquid supply chamber, a container, and an excess liquid collection chamber, with capillary pathways provided as described to extend respectively from the liquid supply chamber to the container, and from essentially the predetermined liquid level in the container to the bottom of the liquid collection chamber at a level below the level of the bottom of the container.
• the volume of the supply chamber is predetermined to be greater than the volume of the container to insure sufficient liquid to "fill" the latter to the desired predetermined level.
• the liquid is conveniently introduced to the supply chamber, and flowed therefrom as described along the provided capillary pathways, completely free of bubble content, into the container; with the excess liquid flowed in turn along the provided capillary pathways from the container to the collection chamber; thereby ultimately resulting in the liquid which is retained in the container residing therein at the precisely predetermined level, and again with a concave meniscus.
• FIG. 1 is a perspective view of a container operatively incorporating therewith new and improved liquid self-levelling means representatively configured and operable in accordance with the teachings of my invention
• FIG. 2 is a top plan view of the container of FIG.
• FIG . 3 is a cross-secitonal view taken essentially along line 3-3 in FIG. 2 ;
• FIG . 4 is an enlarged f ragmentary view of a portion of FIG. 2 ;
• FIGS. 5 nd 6 are respectively cross-sectional views as in FIG. 3, and respectively illustrate the operation of the self-levelling means of my invention essentially at the commencement and completion thereof;
• FIG. 7 is a top plan view of a container operatively incorporating the self-levelling means of my invention, and excess liquid collection means, therewith;
• FIG. 8 is a cross-sectional view taken essentially along line 8-8 in FIG. 7, and illustrates the operation of the self-levelling means of my invention essentially at the commencement thereof;
• FIG. 9 is a cross-sectional view as in FIG. 8 illustrating the operation of the self-levelling means of my invention at the completion thereof, and further illustrates a representative application of the self-levelling means of the invention to use in conjunction with an automated sample liquid analysis system;
• FIG. 10 is a perspective view of a container operatively incorporating the self-levelling means of my invention, and new and improved bubble-free liquid introduction means representatively configured and operable in accordance with the teachings of my invention, therewith;
• FIG. 11 is a top plan view of the container of FIG. 10;
• FIG. 12 is a cross-sectional view taken essentially along the 12-12 in FIG. 11 and illustrating the operations of the self-levelling and bubble-free liquid introduction means of my invention intermediate the same;
• FIG. 13 is a cross-sectional view as in FIG. 12 and illustrating the operations of the self-levelling and bubble-free liquid introduction means of my invention at the completion thereof.
• FIGS. 1, 2, 3 and 4 of the application drawings an essentially conventional, open- topped f usto-conical container is shown at 10; and includes new and improved self-levelling means representatively configured and operable in accordance with the teachings of the currently contemplated best mode of the apparatus and method of my invention as indicated generally at 12.
• the self-levelling means 12 comprise essentially identical container ribs as indicated at 14 and 16, and which are respectively disposed as shown to opposite sides of the container 10 to be diametrically opposed relative thereto.
• Each of the ribs 14 and 16 is formed as shown to commence at, and to be flush with, the interior side wall 18 of the container 10 at precisely the same level 20 within the container; and to extend therefrom up and across the container top wall or lip 22, and down the container exterior side wall 24 to terminate as shown essentially at the container bottom 26.
• commencement of the ribs 12 and 14 at precisely the same level 20 on the container interior side wall 18 the latter will be seen to be uniformly bevelled, as shown at 28, commencing at the level 20 and extending upwardly to the top wall or lip 22 of the container 10.
• these contiguous rib-container surface junctures or corners which are in each instance formed by the juncture of the rib surface with the respective surfaces of the bevelled container interior wall portion 28, the container lip 22, and the exterior container wall 24, are indicated at 30 and 32, respectively, to either side of the rib: while, for rib 16, these rib-container surface junctures of corners, formed as described for rib 14, are indicated at 34 and 36, respectively, again to either side of the rib.
• these rib-container surface junctures or corners 30, 32, 34 and 36 are made as sharp as practical in accordance with the particular material(s) chosen for the container 10 and the ribs 14 and 16, and the particular manufacturing technique(s) employed in the fabrication thereof; it being noted in this regard that a juncture or corner radius as indicated at R in the enlarged fragmentary view of FIG. 4 for corners 34 and 36 of 0.002 inch radius maximum has proven satisfactory in these regards.
• the contiguous, sharp-cornered rib-container surface junctures 30, 32, 34 and 36 will, under appropriate container material surface energy vis-a ⁇ vis contained liquid surface tension conditions as described in greater detail hereinbelow, function as micro-capilarry tubes, thus providing four capillary pathways as respectively formed by surface junctures 30, 32, 34 and 36, and which extend in each instance as heretofore described from level 20 inside of container 10 upwardly and across the container lip 22 and downwardly therefrom essentially to the bottom 26 of container 10; with each of those capillary pathways being inherently effective under the influence of a contained liquid driving force as provided by capillary rise to flow liquid contained in container 10 above the level 20 out of the container, thereby lowering that liquid precisely to that level within the container 10.
• the molecules at the surface of the liquid particle are subjected to an inwardly directed force, while the molecules near but not at the particle surface are also subjected to an inwardly directed force, although of lesser magnitude. It therefore requires a certain amount of work to bring a molecule from the center of the spherical liquid particle to a point near the particle surface.
• the volume of the unconfined liquid particle is increased, as by the introduction of more liquid thereto, molecules will have to be moved from the interior of the spherical particle to the 14 particle surface to account for the increased surface area there, thus requiring the performance of a certain a ⁇ r-unt of work; with the energy required for the same being proportional to the increase in surface area.
• This energy which is expressed in terms of work per unit area as the units of force per unit length, is called surface tension.
• ⁇ P is the pressure change
• pi is the pressure at the interior of the liquid particle po is the air pressure outside the liquid particle
• € is the surface tension of the liquid
• r is the radius of the spherical liquid particle.
• wetting angle or contact angle
• theta This wetting or contact angle depends basically upon the relative attractions of the molecules of three media involved, in this instance, the liquid, the solid which forms the supporting surface, and the surrounding air, and is therefore a function of the relevant physical characteristics of all three of these substances.
• this angle is very sensitive to contaminants, and is dependent in part upon whether the liquid is advancing or receding over the solid supporting surface.
• h (26 * grp) X (cos(theta)) wherein, h is the extent of the rise or fall of the liquid, 6 is the surface tension of the liquid, g is the acceleration of gravity, r is the radius of the tube, ⁇ is the density of the liquid, and theta is the contact angle between the liquid and the tube.
• Equation II Careful examination of Equation II reveals that the 2 ⁇ /r term is pressure change ⁇ P across the liquid-air interface as calculated in accordance with the surface tension of the liquid and the radius of the interface from Equation I; while the cos(theta) term is derived from the contact angle of the liquid with the tube in accordance with the relative attractions of the molecules of the three media involved, namely the liquid, the surrounded air, and the solid . material of the tube. If the liquid molecules are attracted to the solid tube material molecules, the contact angle at the liquid-tube interface will be less than 90 degrees to result in a positive cos( theta) term, and an attraction or rise in the liquid level in the tube. This will also result in concave meniscus for the liquid.
• the contact angle at the liquid-tube interface will be greater than 90 degrees to result in negative cos(theta) term, and a repulsion or fall in the liquid level in the tube.
• the meniscus of the liquid in the tube would be convex.
• Equation II The applicability of Equation II to approximate liquid rise or fall in a tube is limited o situations as described wherein the density of the surrounding medium is much less than the density of the liquid.
• FIGS. 5 and 6 of the application drawings for detailed description of the operation of the self-levelling means 12 of my invention in conjunction with the container 10; it being understood that such description is in accordance with the containment of a liquid as indicated at 40 in FIGS. 5 and 6 which forms a wetting or contact angle of less than 90 degrees with the materials of the container 10 and the ribs 14 and 16.
• FIG. 5 illustrates the filling of the container 10 substantially to capacity at the container lip 22 with the liquid 40, for example by the simple manual pouring of the liquid thereinto.
• filling of the container to capacity as illustrated in FIG. 5 may be readily accomplished by simply pouring the liquid thereinto until the liquid perhaps slightly overflows the container lip 22 thus insuring that the container is full; and this, of course, negates any requirement that the liquid 40 be initially introduced to the container 10 with any degree of time-consuming precision and care to "fill" the container to any predetermined level.
• the meniscus 42 of the liquid 40 in the container 10 will be flipped from convex to concave in accordance with, the wetting of the container and rib material(s) by the liquid and the phenomenon of capillary rise as described, attendant this reduction in liquid level essentially to the level 20 in the container 10.
• the level of the liquid 40 in the container 10 is inherently fixed at a precisely predeterminable level in the container interior below the container lip and virtually coincident with the extent of the ribs 14 and 16 into the container interior, and that the liquid 40 will inherently exhibit a concave meniscus at that level; all totally without requirements for any particular degrees of skill, precision, care, or time expenditures, in the initial filling of the container 10, for moving parts, or for the conduct of operations of any nature beyond the relatively simple initial filling of the container as described with the liquid 40.
• a container assembly representatively configured and operable in accordance with the teachings of the apparatus and method of my invention for use in automated, successive sample liquid analysis systems of the type heretofore described with regard to United States Patents 4,602,995, 4,678,641, 4,758,409 and 4,774,057 is indicated generally at 50 in FIGS. 7, 8 and 9; and will immediately be seen to comprise the container 10 with the self-levelling means 12 as again formed by the ribs 14 and 16 configured and operatively associated therewith as heretofore described.
• the container assembly 50 further includes an outer container member 52 joined as illustrated from the outer surfaces 54 and 56 of the ribs 14 and 16 to the container 10 to be spaced from and surround the same at the container sides and bottom.
• This provides arcuate liquid flow passages as indicated at 58 and 60 between the exterior side wall 24 of the container 10 and the interior side wall 62 of the outer container member 52, as divided by the ribs 14 and 16, and provides a liquid collection space 64 between the exterior wall 66 of the bottom 26 of the container 10 and the interior wall 68 of the bottom 70 of the outer container member of the outer container member 52; it being immediately clear that the liquid collection space 64 will be in liquid flow communication with each of the flow passages 58 and 60, and with each of the capillary pathways which are formed as described by the sharp-cornered rib- container surface junctures 30, 32, 34 and 36, respectively.
• the outer container member 52 which preferably extends as seen in FIGS.
• FIG. 8 depicts the container assembly 50 of my invention immediately upon the completion of the simple filling of the container 10 as heretofore described essentially to capacity with a sample liquid, as indicated at 76, including an initially convex meniscus as indiacted at 78; and makes clear that, within reason, any spillage of the sample liquid 76 as may have occured during the filling of container 10 and overflowed the same will have been effectively contained by the upper wall portions of the outer container member 52 which extend as shown above the lip 22 of the container 10 for downward flow through arcuate flow passages 58 and 60, and containment as representatively illustrated in the collec-tion space 64.
• FIG. 9 depicts the container assembly 50 upon the completion of the flow of that portion of the sample liquid 76 in container 10 above the level 20, up and out of the container interior, across the lip 22, and down the container exterior, along the respective capillary pathways formed by the sharp-cornered rib-container surface junctures 30, 32, 34 and 36, all as heretofore described in detail with regard to FIG. 6, with attendant flip of the sample liquid meniscus 78 from convex to concave; and FIG. 9 makes immediately clear that this portion of the sample liquid 76 will also be containted in the collection space 64 as illustrated along with the sample liquid spillage, if any, upon the flow of that liquid portion into that collection space from those capillary pathways as indicated by the sample liquid flow arrows in FIG. 9 at the lower extremities of those capillary pathways.
• the probe means 80 may, for example, take the general form of those disclosed in United States Patent 4,121,466 issued October 24, 1978 to Mr. Allen Reichler, et al for "Liquid Dispenser With An Improved Probe;" in which instance the probe means 80 would include means to coat the same with a thin layer of an immiscible isolation liquid as set forth in some detail in United States Patent 4,121,466, the disclosure of which is hereby incorporated by reference in this specification.
• an appropriate, predetermined volume of an immiscible isolation liquid, or "lens 5 " thereof as the same is commonly termed, as indicated at 84, may be emplaced in any suitable manner, for example by operatively associated, precisely operable isolation liquid dispenser means as indicated schematically at 85 in FIG. 8, on the concave meniscus 78 of the sample liquid as seen in FIG.
• isolation liquid dispenser means 85 would only be operable to emplace the isolation liquid lens 84 on the concave liquid meniscus after the same had come into being, and prior to operation of the probe means 80 as hereinafter described in detail .
• the surface tension of the sample liquid 76 will function to retain the isolation liquid lens atop the meniscus 78, and the concavity of that meniscus will function to retain the lens 84 precisely certrally disposed relative to the container 10, and thus relative to probe means 80.
• the immiscible isolation liquid for example a fluorinated hydrocarbon liquid, functions to selectively wet the hydrophobic analysis system components, including probe means 80, to the substantial exclusion of the sample liquids under analysis, thus substantially preventing the adherence of those sample liquids to the analysis system components.
• the provision as described in accordance with the teachings of my invention of precisely the same volume of the isolation liquid from lens 84 for aspiration by probe means 80 preceding the aspiration in each instance of the sample liquids 76 in turn from the successively presented container assemblies 50 is also of significant advantage in, on the one hand, insuring that a predetermined, precisely sufficient volume of the isolation liquid as required by the sample liquid analysis system for the carryover minimization task at hand for each sample liquid, is provided; while, on the other hand, insuring that excess and wasteful volumes of the isolation liquid, which are quite expensive and which can adversely affect the accuracy of the sample liquid analysis results, are not provided.
• Container assembly 100 comprises a central, generally cylindrical container 102 in the nature of container 10 as heretofore described with regard to FIGS. 1 through 9, and a generally cylindrical outer container member 104 which surrounds container 100 generally concentrically thereof, and which is spaced therefrom as shown to provide a torous-like space generally indicated at 106 therebetween.
• Vertical dividing walls as indicated at 108 and 110 extend radially as shown between the respective side walls of container 102 and outer container member 104 at a 180° interval thereby dividing space 106 into arcuate spaces 116 and 118. As best seen in FIG.
• the side wall of container 10-2 is divided essentially along the container diameter as indicated at 120 to form semi-cylindrical container side wall portions 122 and 124, with the former being of significantly less height than the latter.
• a generally semi-circular bottom wall 126 extends generally horizontally as shown between the higher container side wall portion 124, intermediate the same, and the side wall of outer container member 104 thereby forming, in conjunction with that container side wall portion, the outer container side wall, and the dividing walls 108 and 110, an open-topped arcuate liquid chamber 128, which is coincident with space 116; while a generally semi-circular bottom wall 129 extends as shown generally horizontally between the lower edge of the lower container side wall portion 122 and the lower portion of the side wall of outer container member 104 thereby forming, in conjunction with that container side wall portion, the outer container side wall, and dividing walls 108 and 110, an open topped arcuate liquid chamber 130 which is coincident with space 118.
• the level of bottom wall 126 of liquid chamber 128 be above the level of the upper edge or lip 132 of the lower portion 122 of the side wall of container 102.
• Automatically operable means for the ready and convenient, oubble-free filling of container 102 with liquid and liquid chamber 128 are indicated generally at 134; and take the form of a rib 136 operatively associated with both the container 102 and the liquid chamber 128 and which, in the manner heretofore described in detail with regard to ribs 14, and 16 of FIGS. 1 through 10, fcrms contiguous, sharp-cornered rib-container surface junctures with the container 102. More specifically, rib 136 extends as best seen in FIGS.
• Self-levelling means configured and operable in accordance with the teachings of the method and apparatus of my invention for the automatic adjustment of the liquid level in container 102 to a precisely predetermined level are indicated generally at 146 in FIGS. 10 through 13 and, in the manner of self-levelling means 12 as heretofore described in detail with regard to FIGS. 1 through 9, comprise a rib 148, diametrically opposed to rib 136 vis-a ⁇ vis container 102, which again forms sharp-cornered rib- container surface junctures with the container 102. More specifically, rib 148 extends as best seen in FIGS.
• FIGS. 12 and 13 from a precisely predetermined level 150 on the interior surface of the side wall portion 122 of container 102 upwardly as shown and over and across the upper edge or lip 132 thereof, and downwardly therefrom along the exterior surface of that container side wall portion substantially to the bottom wall 129 of the liquid chamber 130; thereby forming contiguous rib-container surface junctures 152 and 154 respectively to either side of rib 148, extending in each instance from level 150 in container 102 substantially to the bottom of liquid chamber 130, and providing, as heretofore described, capillary pathways coextensive therewith for liquid flow from level 150 in container 102 into the liquid chamber 130.
• FIGS. 11 through 13 make clear that the level 150 in container 102 is significantly above the level of the bottom 129 of liquid chamber 130; while FIGS. 11 through 13 make clear that the respective volumes of liquid chambers 128 and 130 are, in each instance, greater than the volume of container 102.
• liquid chamber 128 is initially filled in any convenient manner, for example by the simple pouring or dispensing of a liquid as indicated at 156 in FIGS.
• FIG. 12 illustrates this stage in the operation of the container assembly 100 of my invention; with the flow arrows adjacent the capillary pathway formed by the sharp-cornered surface juncture 142 of rib 136 with side wall portion 124 of container 102 illustrating the flow of liquid 156 from chamber 128 into container 102; and the flow arrows adjacent the capillary pathway formed by the sharp-cornered surface juncture 152 of rib 148 with side wall portion 122 of container 102 illustrating the concomitant flow of the liquid 156 from container 102 to chamber 130.
• FIG. 13 illustrates this final, insofar as flow of the liquid 156 is concerned, condition of the container assembly 100, and makes clear that the meniscus 158 of the liquid 156 in container 102 will again be concave.
• the container assembly 100 of FIGS. 10 through 13 is particularly adapted for use as a microsample cup of the nature disclosed in United States Patent 4,758,409 in an automated, successive sample liquid analysis system.
• a precisely predetermined volume or "lens" of an appropriate isolation liquid as indicated at 160 in FIG. 13 may be disposed on the liquid 156 in container 102 and maintained centrally thereof by the concave meniscus 158, to significant advantage with regard to the effective minimization of sample liquid carryover as heretofore described in some detail with regard to isolation liquid lens 84 of FIG. 9.
• the volume of container 102 would be quite small, for example 10Q microliters, while the inner diameter of the container 102 at the upper edge or lip 132 thereof would, for example, be as small as 0.15 inches.
• direct filling of the container 102 in the manner disclosed for the filling of the microsample cup of United States Patent 4,758,409 can sometimes prove difficult, even through use of an appropriately small pipette, due of course to the very small inner container diameter in question.
• microbubbles in the very small sample liquid volumes under discussion, especially upon the handling and dispensing thereof by pipette into an extremely small container, can also prove problematical;, tt being clear to those skilled in this art that the presence of such microbubbles in the sample liquid contained in a .microsample cup of the nature disclosed in United States Patent 4,758,409 can adversely impact upon the overall accuracy of the sample liquid analysis results by lessening the actual volume of sample liquid aspirated from the microsample cup by the probe means for supply to the sample liquid analysis system, and/or by interfering with the essentially central placement, and thus aspirated volume, of an isolation liquid lens as may be emplaced thereon as described.
• Representative materials for use in the formation of the container of my invention for operation as described with essentially aqueous liquids for example human blood sera sample liquids
• glass-filled plastics such as polyvinylchloride or polyethylene, with which such liquids will form a contact angle of less than 90° to readily "wet" the same as required for capillary action.
• the advantages of these glass-filled plastics are ready availability, relatively low cost, general chemical inertness, and suitable strength characteristics.
• the same are readily injection moldable, which is a preferred method for the fabrication of the container of my invention.
• plastics again for example polyvinylchloride, to which an appropriate surfactant, for example ethlylene oxide, has been added, or which have been plasma treated in the presence, for example, of oxygen to, in either instance, raise the surface energy of the plastic in question to an extent sufficient to insure the formation therewith by essentially aqueous liquids of a contact angle of less than 90° as required for capillary action to occur.
• a non-plactic material which is particularly suitable for use in the formation of the container of my invention for operation as described with essentially aqueous liquids is glass which is readily "wettable" by those liquids.
• the container of my invention is preferably fabricated as an integral unit; but, for other and different applications of the container it is not beyond the scope of the apparatus and method of my invention that the ribs be fabricated separately from the container member (s) and simply emplaced thereon, or affixed thereto in any appropriate manner, prior to utilization of the container.
• the level to which the liquid in the container is adjusted may as a practical matter be freely chosen in the fabrication of the container and ribs to range from a level immediately below the full capacity level of the container at the relevant container lip, to a level immediately above the container bottom.
• the liquid flow rate(s) both out of and into the container in instances wherein the latter is relevant in all applications of my invention will depend in large measure upon the number or ribs, and thus of capillary pathways provided, the liquid "head" in question which drives that liquid flow in each instance, and the respective lengths of the capillary pathways, it will be immediately clear to those skilled in this art that each of those parameters may be readily varied from those as representatively disclosed herein.
• the container 10 of FIGS. 1 through 6 could include only one rib, or could alternatively include more than two of the same; while whatever number of ribs are provided need not extend completely to the container bottom 26.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Analytical Chemistry (AREA)
• Clinical Laboratory Science (AREA)
• General Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Health & Medical Sciences (AREA)
• Hematology (AREA)
• Physics & Mathematics (AREA)
• Sampling And Sample Adjustment (AREA)
• Details Of Rigid Or Semi-Rigid Containers (AREA)
• Automatic Analysis And Handling Materials Therefor (AREA)
• Control Of Non-Electrical Variables (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)

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• 1989
  • 1989-05-30 AU AU37429/89A patent/AU645961B2/en not_active Expired - Fee Related
  • 1989-05-30 WO PCT/US1989/002345 patent/WO1990015333A1/en not_active Application Discontinuation
  • 1989-05-30 JP JP1502734A patent/JPH04505048A/ja active Pending
  • 1989-05-30 EP EP19890906603 patent/EP0474630A4/en not_active Withdrawn
  • 1989-10-16 IL IL92005A patent/IL92005A0/xx not_active IP Right Cessation
  • 1989-12-07 ES ES898904161A patent/ES2017885A6/es not_active Expired - Fee Related
  • 1989-12-18 CA CA002005782A patent/CA2005782A1/en not_active Abandoned
• 1991
  • 1991-11-29 DK DK193891A patent/DK193891A/da not_active Application Discontinuation

Patent Citations (4)

Non-Patent Citations (1)

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