Abstract: Microstructure for fluids provided in a rotatable disc (D) having a U-shaped volume-defining structure (7) connected at its base to an inlet arm of a U-shaped chamber (10).

Abstract: A device for centrifugation and robotic manipulation of specimen samples, including incubating eggs, and uses thereof are provided. The device may advantageously be used for the incubation of avian, reptilian or any type of vertebrate eggs. The apparatus comprises a mechanism for holding samples individually, rotating them individually, rotating them on a centrifuge collectively, injecting them individually with a fixative or other chemical reagent, and maintaining them at controlled temperature, relative humidity and atmospheric composition. The device is applicable to experiments involving entities other than eggs, such as invertebrate specimens, plants, microorganisms and molecular systems.

Abstract: The present invention relates to the field of photometric analysis, particularly to photometric analysis apparatuses which use disk-shaped rotors, in which the rotors are loaded automatically.

Abstract: A specimen tube has a tubular body having one closed end and an opposite open end, a cap having an end wall with flat outer face and an opposite inner face and a formation securing it to the open end of the tubular body, and a pierceable membrane disk pressed against the inner face of the end wall. Labeling can be applied to the end-wall outer face.

Abstract: A system and method for detecting the presence of submicron sized particles in a sample taken from the environment includes a collecting a sample from the environment and purifying and concentrating the submicron particles in a sample based on the size of the particles. The purified and concentrated particles are detected with an apparatus which includes an electrospray assembly having an electrospray capillary, a differential mobility analyzer which receives the output from the capillary, and a condensation particle device for counting the number of particles that pass through the differential mobility analyzer.

Abstract: The invention relates to a method and an apparatus for performing an assay on chemical, biochemical, or biological fluids. The apparatus includes an assay chamber for fluid reactions and a centrifugal force activated-valve for controlling fluid movement through the assay chamber. An active surface can be positioned in the assay chamber to react with fluids passed through the assay chamber. The active surface may contain biomolecular probes. The biomolecular probes can be DNA, DNA fragments, RNA, RNA fragments, reagents, protein, protein fragments, lipids, and lipid fragments. The apparatus is particularly useful when multiple reactions, dilutions, or washing steps are required to determine a final answer. The centrifugal force activated-valve provides positive control over fluid in the assay chamber and allows for repeated use of the same chamber for multiple reaction steps. The apparatus can be disposed of after an assay to eliminate potential contamination from reuse of the same apparatus.

Abstract: A tube and float system for use in separation and axial expansion of the buffy coat includes a transparent or semi-transparent, flexible sample tube and a rigid separator float having a specific gravity intermediate that of red blood cells and plasma. The float includes a main body portion of reduced diameter to provide a clearance gap between the inner wall of the sample tube and the float. One or more protrusions on the main body portion serve to support the flexible tube. During centrifugation, the centrifugal force causes the diameter of the flexible tube to expand and permit density-based axial movement of the float in the tube. The float further includes a pressure relief system to alleviate pressure build up in the trapped red blood cell blood fraction below the float, thereby preventing red blood cells from being forced into the annular gap containing the buffy coat layers.

Abstract: The invention relates to a method for the enrichment or depletion of tumor cells from a body fluid, in which a cell separation medium of specific density is overlaid with the body fluid and is centrifuged. A kit suitable for this method is likewise provided.

Abstract: A specimen centrifuge system includes a centrifuge unit including a plurality of specimen centrifuges which are stacked in a plurality of layers in a vertical direction, a rack conveyor which is provided along a horizontal conveyance line, and a rack elevator which is provided along a vertical conveyance line. The rack elevator has a robot arm device which moves the specimen-container rack from the rack conveyor to the rack elevator and from the rack elevator to the rack conveyor and moves the specimen-container rack from the rack elevator to one of the specimen centrifuges and from one of the specimen centrifuges to the rack elevator.

Abstract: An adapter for use with a centrifuge. Features of the adapter allow for less friction during extraction of the adapter and separation efficiency by preventing disturbances to the separated materials. In addition, the adapter includes features that support the walls of a sample container and prevent force from damaging the sample container during a centrifuge separation procedure.

Abstract: An apparatus that allows for separating and collecting a concentrated fraction of a fluid, such as a whole blood sample, adipose tissue, or a bone marrow sample. The apparatus, when used with a centrifuge, allows for the creation of at least three fractions in the apparatus. It also provides for a new method of extracting the buffy coat phase from a whole blood sample. The apparatus includes a container to be placed to a centrifuge after being filled with a whole blood sample. A buoy or fraction separator, which has a density less than that of red blood cells of a whole blood sample, is disposed in the container. During the centrifuge process the buoy separates the red blood cells from another fraction of the whole blood. After the centrifuge process is finished a plunger is used to produce at least two other fractions, including a plasma fraction and a buffy coat. Then, the buffy coat may be removed from the container without commingling the fractions of the sample.

Abstract: The invention relates to a rotary drive adapted for creating liquid flow in rotatable microfluidic discs. A rotary drive for spinning a disc shaped substrate having microfluidic structures formed therein for the flow control of microliter and/or nanoliter volumes of liquid by centrifugal force is suggested, comprising a motor with a spindle having an axis of rotation. A rotary member is connected for rotation with the spindle and driven for rotation relative to a stationary member, the rotary member being formed with a top plane having a centering guide for receiving the disc so as to force a symmetry axis of the disc into alignment with said axis of rotation. A vacuum source is connected with the stationary member and communicating with the rotary member or a part thereof rotating with the rotary member for applying sub-pressure to the disc when spinning the disc about its symmetry axis. Preferably, the rotary member is journalled for contact-free rotation relative to the stationary member.

Abstract: A system for separating a composite fluid into component parts thereof, including: a centrifuge having a rotor with a separation space and at least two valve members disposed thereon and a container set having a separation container adapted to be disposed in the separation space of the rotor and first and second collection containers connected to the separation container by a first and a second tubes. The tubes are adapted to be disposed in operative relationship with the valve members so that flow through the tubes may be controlled thereby. Three components of the composite fluid may be separated therefrom by the present system and two components may be moved to the collection containers. The container set may further include a third collection container connected to the separation container by a tube, and a third component may thus be moved to this third container.

Abstract: The automated sample-on-solid-support processing system of the present invention comprises a computer-based control unit and a main unit comprising a variable-speed centrifuge having an openable vacuum-tight chamber and a centrifuge rotor with a plurality of multi-sample holding positions, a liquid solvent supply subsystem which feeds solvent to a plurality of dispensing stations in the centrifuge chamber, a temperature control subsystem, and a vacuum subsystem. A sample/collection container includes a plurality of wells, each for separating a sample from its solid support when solvent is dispensed into the wells and the centrifuge is activated at a low speed. Operation of the centrifuge at high speed concentrates the cleaved sample in collection wells. In the preferred embodiment bar code reader or other identification means, preferably a non-contact reader, can be included in the chamber to allow sample carriers to be identified.

Abstract: In a rotary evaporator, the rotating speed of the rotating flask is automatically controlled or regulated dependent upon a detected process value, particularly the vibration behavior or the mass moment of inertia of the rotating flask.

Abstract: A device and method is provided for separating heavier and lighter fractions of a fluid sample. The device includes a plurality of constituents comprising a container and a composite element in the container. The composite element is a separator comprising at least two components and more particularly an elastic portion and a plug member. A fluid sample is delivered to the container and the device is subjected to centrifugation whereby the centrifugal load causes the elastic portion of the separator to deform so that the separator migrates into the fluid sample and stabilizes between the heavier and lighter fractions of the fluid sample. The elastic portion of the separator will resiliently return to its initial configuration upon termination of the centrifugal load such that the elastic portion sealingly engages the container and separates the heavier and lighter fractions of the fluid sample.

Abstract: The invention provides a method and apparatus for separating blood into components, may be expanded to include other types of cellular components, and can be combined with holographic optical manipulation or other forms of optical tweezing. One of the exemplary methods includes providing a first flow having a plurality of blood components; providing a second flow; contacting the first flow with the second flow to provide a first separation region; and differentially sedimenting a first blood cellular component of the plurality of blood components into the second flow while concurrently maintaining a second blood cellular component of the plurality of blood components in the first flow. The second flow having the first blood cellular component is then differentially removed from the first flow having the second blood cellular component.

Abstract: A centrifugal separator (4), comprising a drive motor (M1), a rotor (41) rotated by the motor (M1) about a specified axis, and a cubette (42) swingably suspended by the rotor (41), wherein the cubette (42) holds a specimen to be tested, the cubette (42) is rotated according to the rotation of the rotor (41) and takes an inclined attitude to a vertical direction and, in this state, the specimen to be tested is centrifugally separated.

Abstract: A removable conformal liner for a centrifuge container is described. The liner has a flexible or semi-rigid body with an opening for introducing a sample. When the liner is inserted into an internal cavity of a centrifuge container, the body of the liner conforms to the interior cavity. The liner body may be made of a material that is sufficiently resilient to allow a reversible deformation of the body by folding, twisting, collapsing, rolling, or pleating.

Abstract: The invention provides a method, apparatus and system for separating blood and other types of cellular components, and can be combined with holographic optical trapping manipulation or other forms of optical tweezing. One of the exemplary methods includes providing a first flow having a plurality of blood components; providing a second flow; contacting the first flow with the second flow to provide a first separation region; and differentially sedimenting a first blood cellular component of the plurality of blood components into the second flow while concurrently maintaining a second blood cellular component of the plurality of blood components in the first flow. The second flow having the first blood cellular component is then differentially removed from the first flow having the second blood cellular component. Holographic optical traps may also be utilized in conjunction with the various flows to move selected components from one flow to another, as part of or in addition to a separation stage.

Abstract: The invention concerns a method comprising detecting tubes inside carriers (P), detecting an expected imbalance of the centrifuge (CE) and, when said detection reveals the presence of such an imbalance owing to the presence of an insufficient number of carriers (P) or an odd number of carriers (P), the method consists in: simulating the load of the centrifuge incorporating the incomplete carrier (P), selecting a balance-restoring carrier based on the number of tubes missing in the incomplete carrier (P), determining the boat of the centrifuge (CE) wherein the balancing carrier should be placed and installing said carrier in the boat.

Abstract: A method for separating a multi-phase mixture (50) into a liquid phase (54) and a dry phase (52) with a specified dry matter concentration. A decanting centrifuge (100) with an annular immersion disk (14) and a weir arranged at an end face of a centrifuge drum (20) are used. After start-up of the centrifuge drum (20), the multi-phase mixture (50) is introduced into the centrifuge drum (20). The dry phase (52) and the liquid phase (54) are drawn off. The liquid level in the centrifuge drum (20), is controlled by the weir and compared to a tolerance range until the specified dry matter concentration is reached. The weir is positioned so reaction to concentration changes in the multi-phase mixture (50) is possible in both directions. The speed of the centrifuge drum (20) is lowered incrementally and the weir position adjusted, so the dry phase concentration remains constant.

Abstract: A specimen centrifuge apparatus includes a specimen container carry-in system and a specimen container carry-out system. The specimen container carry-in system has a specimen container carry-in conveyor for loading pre-processed specimen containers into specimen centrifuge units stacked one on another in a centrifuge device, a carry-in elevator, a carry-in transfer arm, and a loading arm. The specimen container carry-out system has a specimen container carry-out conveyor for unloading the processed specimen containers from the specimen centrifuges, a carry-out elevator, a carry-out transfer arm, and an unloading arm.

Abstract: A microfluidic device provides separation of particles in a liquid sample, particularly, separation of a sample of whole blood into its components for further analysis. Separation into red blood cells and plasma occurs within a few seconds after the blood sample has been transferred into a separation chamber with the application of centrifugal force of less than about five times gravity. With the application of greater force measurement of hematocrit is possible.

Abstract: A combinatorial, high-throughput screening method is described for developing new coatings having a performance characteristic of a coating property which results in a substantial increase in the discovery rate of new coating materials. The method includes the steps of providing an array of wells (18) for receiving candidate coating materials having a parameter; placing coating materials in each well (16) while varying the coating material parameter correlating the coating material position in the array to the variation of the coating material parameter; applying a coating leveling force to and optionally drying the coating materials in the array of coating wells (19); testing the coatings with regard to the desired performance characteristic (21) and correlating the result of the test to the well position in the array that thereby coating materials having the desired performance characteristic may be discovered.

Abstract: This invention relates to clinical diagnostic assays and related optical bio-discs and a disc-reading apparatus. The invention is directed to a method for determining the blood cell type of an individual.

Abstract: Optical bio-discs for biochemical analysis, bio-disc analysis systems and biochemical analysis methods are described herein. In one embodiment, the bio-disc includes a sample analysis circuit that includes a separation membrane for separating an investigational feature of a sample. The bio-disc also includes a conjugate release pad, and an analysis membrane containing analysis zones that may be analyzed for the presence of analytes. An analysis method includes providing a sample to a separation membrane in a bio-disc, separating an investigational feature from the sample using a separation membrane, mixing reagents that include signal elements for detecting an analyte with the investigational feature so as to form a reagent-investigational feature mixture and capturing an analyte with a signal element bound thereto in an analysis zone on an analysis membrane.

Abstract: A microfluidic accumulating and proportioning component, including: a reservoir including an aeration port and an outlet disposed below for a liquid, capillary cavities in the reservoir, a displacement chamber which is disposed at least partly at the same level as the reservoir, with an inlet disposed above and a proportioning outlet disposed below for a liquid, and a rising capillary channel connecting the outlet of the reservoir to the inlet of the displacement chamber.

Abstract: A nucleic acid-bound polypeptide produced by binding a nucleic acid to a polypeptide, a method of producing the nucleic acid-bound polypeptide, and applications of the nucleic acid-bound polypeptide, including immunoassays for an antigen or antibody, such as an agglutination immunoassay are provided.

Abstract: This invention relates to clinical diagnostic assays, related optical bio-discs, and a disc-reading apparatus. The invention is directed to methods and apparatuses for performing immunohematology assays using an optical bio-disc analysis system. The invention is further directed to an optical bio-disc for performing an immunohematologic assay including a substrate having encoded information associated therewith. The encoded information may be readable by a disc drive assembly to control rotation of the disc. The disc may also include at least one target zone or capture zone associated with the substrate. The target zone is disposed at a predetermined location relative to a center of the substrate. The disc further includes a plurality of capture antibodies immobilized within the target zone, a flow channel, fluidic circuit, or analysis chamber associated with the target zone, and an input site in fluid communication with the analysis chamber.

Abstract: A process includes coating a cylinder having an inner wall and a cylinder axis with a gel coating on the inner wall. Then a specimen mixture including solvent is made to flow through the cylinder while the cylinder is being continuously rotated. The specimen mixture is initially directed to flow along the cylinder axis and such that specimen particles from the specimen mixture are accelerated off the cylinder axis toward the inner wall, so as to form a film of specimen particles embedded into the gel coating.

Abstract: This invention provides methods and apparatus for detecting and quantifying particulate matter suspended in a fluid. Specifically, the invention provides an integrated, affinity-binding based, analytical system comprising a platform for performing an affinity-binding based assay for specifically binding particulates including microbial cells, and a detection means for detecting the particulates specifically bound to a defined surface or chamber comprising the platform. Methods for using the analytical systems of the invention are also provided.

Abstract: A centrifuge system with an externally positioned sensor assembly for detecting the separation of components in a fluid sample, such as platelets in a blood sample. The system includes a centrifuge with a drive portion and a rotor portion with a sample reservoir or centrifuge bag for receiving and containing a fluid sample during rotation of the rotor portion. An external sensor assembly is positioned relative to the centrifuge to direct a radiation beam from a radiation source through the rotor portion and the centrifuge bag and to allow a detector to receive the lower-intensity radiation beams at a location external to the rotor portion. In one embodiment, the rotor portion is fabricated from a transparent material and extends radially outward from the sides of the drive portion to allow the radiation source and detector to be positioned externally on opposing sides of the extending rotor portion.

Abstract: An apparatus for analyzing liquid samples packed in tubes (6) closed with a top (7) capable of being perforated, includes a support (4) for the tubes and a unit (8) for sampling an aliquot from each tube and delivering it into a receptacle for treatment and/or analysis, the unit (8) including a hollow needle (45) connected to a suction/delivery device and vertically mobile; the support (4) has a circular tray provided with several tube-holders (5) on its periphery and capable of rotating about a vertical axis to bring a position successively and selectively the tubes (6) borne by the tube-holders (5) in line with the unit (8); each tube-holder (5) is connected to the tray (4) through a linkage (31) with two degrees of freedom.

Abstract: Sample processing systems and methods of using those systems for processing sample materials located in devices that are separate from the system are disclosed. The sample processing systems include a rotating base plate on which the sample processing devices are located during operation of the systems. The systems also include connection apparatus that allow for rapid and easy removal and/or replacement of base plates.

Abstract: There has been invented an apparatus comprising a separation barrier for excluding denser cell materials from less dense cell materials after centrifuging of the cells so that selected materials can be withdrawn from the less dense cell materials without inclusion of the denser cell materials or clogging of sampling equipment with denser cell materials. Cells from which selected material is to be withdrawn are centrifuged, either as cells or cells in media. Once the denser cell materials are isolated in a layer by centrifugal force, an invention screen or seive is submerged in the less dense cell material to a level above the layer of denser cell materials to isolate the denser cell materials from the less dense cell materials, preventing mixing of the denser cell materials back into the less dense cell materials when the cells or the cells in media are no longer being centrifuged and to prevent clogging of sampling equipment with denser cell materials.

Abstract: A system for automated operation of a blood separation system controlling the input of blood samples, the separation of blood components, and the discharge of the components. The system includes a blood reservoir and centrifuge for receiving blood samples and separating the blood components. A sensor determines when adequate separation has been achieved and a controller receives signals from the sensor to operate a centrifuge drive assembly to achieve desired separation. Separation may be based on a calibrated rotation time for the centrifuge as measured by a timer. An input pump pumps blood samples to the blood reservoir, and an outlet pump removes separated samples from the blood reservoir. The inlet and outlet pumps are operated by the controller, and the inlet pump may be operated to discharge separated components not collected by the blood separation system, whereby additional sample volume is added for ongoing operation.

Abstract: Disclosed is a method for performing the steps of nucleic acid template purification, a thermocycling reaction and purification of the products of the thermocycling reaction characterised in that the steps take place sequentially in a microfluidic disc. Also disclosed is a microstructure for fluids comprising at least one inlet opening connected to a first chamber incorporating a means for purifying template nucleic acid which, in turn, is connected to a second chamber incorporating a means for a thermocycling reaction which, in turn, is connected to a third chamber incorporating a means for purifying products of the thermocycling reaction, and a microfluidic disc comprising a plurality of such microstructures.

Abstract: A method for dispensing droplets of a liquid to a microsystem in the form of a disc comprising a target area (TA0I) in its surface, said disc preferably being a microfluidic disc comprising a microchannel structure with an inlet port that is a target area (TA0I). The method is characterized by comprising the steps of: i) providing (1) said disc which has a triggering mark, and (2) a dispenser arrangement comprising: a) a spinner for rotating the disc around its axis, b) a drop dispenser permitting dispensation of droplets to inlet port I, c) a fixed trigger position outside the disc, and d) a controller which is capable of triggering the dispensation of a droplet into (TA0I) as a function of the triggering mark passing the trigger position, ii) placing the disc in the spinner and programming the controller with values for dispensing parameters that will give dispensation of the droplets to TA0I, iii) dispensing the droplets. The invention also comprises the dispenser arrangement as such.

Abstract: An apparatus for evaporating liquid samples contained in sample holders mounted within a chamber and by rotated by the rotor during an evaporation process in which the pressure in the chamber is reduced below atmospheric and the sample holders are rotated at high speed so as to exert centrifugal force on the contents of the holders. Heat is supplied to elevate the temperature of the liquid component of the samples to assist in the evaporation process. The temperature of the sample material is continuously or regularly monitored during the evaporation process and temperature signals are transmitted to a remote computing means which is programmed to generate a control signal for controlling the supply of heat to the samples and controlling the evaporation process. The temperature may be sensed by a probe in a sample holder containing an evaporating liquid sample, or in an adjoining sample holder containing a buffer liquid. The rotational speed is also sensed and a speed signal conveyed to the computing means.

Abstract: A device for centrifuging various samples of a product or a mixture of products which are chemical or biological, the device including a vessel which is open at the top and contains a vertical central shaft driven in rotation by a rotary driving means, a horizontal plate mounted interlocked in rotation on the central shaft and provided on its surface with a plurality of through orifices for the mounting of tubes which are each intended to contain a volume of a sample to be centrifuged, these through orifices having a substantially elongate shape with front and rear walls inclined at an acute angle of less than 90 degrees relative to the horizontal, and means for indexing the position of the plate each time the plate stops, in order to position through orifices of the tubes at predetermined sites.

Abstract: A centrifuge labware includes a container and a removable, non-threaded lid. The container has a top opening which is at least about 90% of the cross-sectional area of the container.

Abstract: Automatic diagnostic apparatus includes: a controller for controlling operation of the apparatus and for processing data; a sensing system operably connected to the controller for performing an assay, preferably an electrochemical assay (more preferably an electrochemical immunoassay), of a sample and communicating data from the assay to the controller; voltage supply means for applying a potential differential to the sensing system; and output means for communicating processed data to a user.

Abstract: Apparatus, methods, and systems for processing sample materials that may be presented in a standard microtiter plate are disclosed. The present invention provides a bridge between the standard microtiter plate systems, methods, protocols, etc. with their stationary wells and rotating sample processing devices that allow users to obtain the rapid processing advantages of the newer sample processing devices while retaining the benefits of the standard microtiter plate formats.

Abstract: A simple, efficient apparatus and method for separating layers of immiscible or partially miscible liquids useful in methods of high-throughput combinatorial organic synthesis or parallel extraction of large libraries or megaarrays of organic compounds is disclosed. The apparatus and method are useful, whether as part of an automated, robotic or manual system for combinatorial organic synthesis or purification (extraction). In a preferred embodiment, an apparatus and method for separating layers of immiscible or partially miscible liquids compatible with microtiter plate type array(s) of reaction vessels is disclosed. Another application of centrifugation based liquid removal was found for washing the plates in biological assays or synthesis on modified substrates.

Abstract: A rotatable rotor for separating components contained in a fluid, comprising an annular base having a first annular channel and an annular cover having a second annular channel for holding a flexible doughnut-shaped centrifuge bag therebetween. The cover has one or more radially spaced apart concentric indicator lines for monitoring the separation of the components. When the base and cover are superimposed, the first and second channels define an annular interior chamber having an off-centered figure eight configuration. The base and cover each comprise a grooved column axially centered and extending from the base top surface and the cover bottom surface, respectively. The flexible bag comprises inner and outer tubes extending from the core of the bag and which are seated in the column grooves to ensure that the bag is fixably rotatable with the rotor.

Abstract: The present invention relates generally to a fractionator for collecting at least one of a plurality of segregated components from a segregated sample disposed in a sample tube. The fractionator has a head with a head surface at its forward end. The head may be configured to form a slideable seal with the inside surface of a sample tube. A collection port is disposed forward of the head surface, and a fluid passageway is in fluid communication with the collection port and is configured and arranged to allow fluid transport from the sample tube to a sample receptacle. The fractionator may have a valve in fluid communication with the collection port and may have a valve controller configured and arranged to operate the valve based, at least in part, on the location of the collection port with respect to a sample disposed in the sample tube.

Abstract: The present invention relates to a kit for determining feline blood type, wherein the kit includes a mixture comprised of a first monoclonal antibody and a second monoclonal antibody, wherein both antibodies recognize feline blood group specific A antigens. The present invention also relates to a method for determining feline blood type, wherein the method utilizes two distinct monoclonal antibodies, which recognize feline blood group specific A antigens.

Abstract: The automated sample-on-solid-support processing system of the present invention comprises a computer-based control unit and a main unit comprising a variable-speed centrifuge having an openable vacuum-tight chamber and a centrifuge rotor with a plurality of multi-sample holding positions, a liquid solvent supply subsystem which feeds solvent to a plurality of dispensing stations in the centrifuge chamber, a temperature control subsystem, and a vacuum subsystem. A sample/collection container includes a plurality of wells, each for separating a sample from its solid support when solvent is dispensed into the wells and the centrifuge is activated at a low speed. Operation of the centrifuge at high speed concentrates the cleaved sample in collection wells. In the preferred embodiment bar code reader or other identification means, preferably a non-contact reader, can be included in the chamber to allow sample carriers to be identified.

Abstract: Vessel systems for treating and/or storing liquids are provided. The vessel systems comprise a two-dimensional vessel arrangement with a plurality of vessels which are open at the top and which are interconnected to form a unit, and a two-dimensional closure arrangement which has an arrangement of closure elements corresponding to the vessel arrangement and by means of which the openings of the vessels can be closed. Each vessel of the vessel arrangement is connected to at least one other vessel of the vessel arrangement via a preferably flexible connecting member. Each of the closure elements is connected to at least one other closure element of the closure arrangement via a flexible connecting member which allows a change of the distance between the closure elements.