Abstract: An apparatus that allows for separating and collecting a fraction of a 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. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: A rotor is provided for the centrifugal separation of a composite fluid, such as animal or human blood, into components. An inner surface of the rotor includes at least one hydrophobic area having a first surface energy sufficiently low to provide a flow path for a lower density fluid component to flow to the bottom of a central collection chamber after centrifugal separation. A method of separating a composite fluid into components using such a rotor is also provided. Additionally, a method of manufacturing such a rotor is provided.

Abstract: An apparatus is disclosed that allows for separating and collecting a fraction of a 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. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: An apparatus that allows for separating and collecting a fraction of a sample. The apparatus, when used with a centrifuge, allows for the creation of at various fractions in the apparatus. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient. Also selected fractions from the sample can be applied to a patient, either alone or as part of a mixture.

Abstract: A platelet collection device comprising a centrifugal spin-separator container with a cavity having a longitudinal inner surface. A float in the cavity has a base, a platelet collection surface above the base, an outer surface. The float density is below the density of erythrocytes and above the density of plasma. The platelet collection surface has a position on the float which places it below the level of platelets when the float is suspended in separated blood. During centrifugation, a layer of platelets or buffy coat collects closely adjacent the platelet collection surface. Movement of a float having a density greater than whole blood through the sedimenting erythrocytes releases entrapped platelets, increasing the platelet yield.

Abstract: An apparatus that allows for separating and collecting a fraction of a 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 and mesenchymal stem cells from bone reaming material. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: A separator that uses centrifugation to fractionate a suspension such as blood comprises a separation container and a buoy. The buoy is carried in the separation container and has a tuned density that is configured to reach an equilibrium position in a suspension. The guide surface is carried on the buoy upper surface and is inclined to an accumulation position near a buoy perimeter. The buoy suspension fractionation system can be used in a method of isolating a fraction from a suspension, and in a method for re-suspending particulates for withdrawal.

Abstract: An apparatus is disclosed that allows for separating and collecting a fraction of a 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. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: Methods for using a centrifuge are presented. A vessel containing a sample and a separator substance is placed within a centrifuge. Upon sufficient centrifugation, the sample separates into two or more fractions separated by the separator substance. The centrifuge exposes the separator substance to a sufficient energy to polymerize the separator substance to produce a hardened barrier between the fractions.

Abstract: A method and apparatus for separating and concentrating a selected component from a multi-component material. The multi-component material may include a whole sample such as adipose tissue, whole blood, or the like. The apparatus generally includes a moveable piston positioned within a separation container and a withdrawal tube that is operable to interact with a distal end of the collection container past the piston. Material can be withdrawn through the withdrawal tube.

Abstract: Methods and devices for preparing a solid-fibrin web are provided. One method may include drawing blood from a patient, separating plasma from the blood, contacting the plasma with a calcium-coagulation activator and concurrently coagulating and axially centrifuging the plasma to form the solid-fibrin web. The solid-fibrin web may be suitable for regenerating body tissue in a living organism. Devices used in the methods may also be provided.

Abstract: Contemplated whole blood separators tubes include a curable composition with a density intermediate to the density of serum and the cell-containing fraction. After centrifugation, the curable composition is located between the serum and the cell-containing fraction and preferably irradiated with UV light to initiate a curing reaction in which the curable composition solidifies to a barrier that is immobilized and resistant to breakdown at freezing temperatures and extended storage.

Abstract: Methods of producing collection tubes are presented. The methods include providing a separator substance that can rapidly polymerize in a short time to a desired hardness and disposing the separator substance within the lumen of the tube. The separator substance is formulated to have a density between an average density of a serum fraction of whole blood and a cell-containing fraction of whole blood, and to be flowable with whole blood. Upon centrifugation of a tube having blood, the separator substance forms a barrier between the whole blood fractions. The barrier rapidly hardens forming a solid barrier when triggered by a suitable energy source.

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: A platelet collection device comprising a centrifugal spin-separator container with a cavity having a longitudinal inner surface. A float in the cavity has a base, a platelet collection surface above the base, an outer surface. The float density is below the density of erythrocytes and above the density of plasma. The platelet collection surface has a position on the float which places it below the level of platelets when the float is suspended in separated blood. During centrifugation, a layer of platelets or buffy coat collects closely adjacent the platelet collection surface. Platelets are then removed from the platelet collection surface. Movement of a float having a density greater than whole blood through the sedimenting erythrocytes releases entrapped platelets, increasing the platelet yield.

Abstract: The present invention provides a fat separator device having a container with a spout portion and a cover portion releasably attached to the container. The cover portion including a surface having at least one aperture to allow for passage of a liquid through the cover portion and a plug portion extending down from the surface, the plug portion being operable to releasably cover the spout portion of the container.

Abstract: An apparatus is disclosed that allows for separating and collecting a fraction of a 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. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: Some embodiments include a valve positioned within a test tube to maintain a separation between components of liquid with different densities after centrifugation. The valve preferably includes a cylindrically shaped housing with a conical plug configured to nest within the housing. The plug is not in contact with the housing during centrifugation, but comes into position post-centrifugation.

Abstract: An apparatus that allows for separating and collecting a fraction of a 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. A buoy system that may include a first buoy portion and a second buoy member operably interconnected may be used to form at least three fractions from a sample during a substantially single centrifugation process. Therefore, the separation of various fractions may be substantially quick and efficient.

Abstract: A separating mechanism for inserting in a receptacle chamber of a container receptacle having a longitudinal axis comprises two adjacently disposed components and a sealing device which is directed towards an internal wall of the container receptacle. The components have two ends spaced apart from one another in the direction of the longitudinal axis, and a flow passage extends therebetween. The components can be applied against the internal wall by at least one pressing element and, in an initial position, the flow passage is established between the adjacently disposed components spaced apart from one another by the pressing element.

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: A composition for blood serum or plasma separation which has improved compatibility between a cyclopentadiene oligomer and a phthalic ester and generates no oily ingredient suspending in the blood serum or plasma after centrifugal separation regardless of the conditions for the centrifugal separation; and a vessel for blood examination which contains the composition. The composition for blood serum or plasma separation comprises: a polycyclic hydrocarbon compound having an unsaturated and/or saturated cyclic structure in the molecule and having a solidifying point or pour point of 0° C. or lower; a cyclopentadiene oligomer; and a phthalic ester.

Abstract: A device and method 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 a deformable bellows, a ballast mounted to the lower end of the bellows, and a float is engageable with an upper end of the bellows. A fluid sample is delivered to the container and the device is subjected to centrifugation whereby the centrifugal load causes the ballast to move toward the bottom of the tube and causes an elongation and narrowing of the bellows. The separator then moves down the tube and stabilizes in a position between the separated phases of the fluid sample. Termination of the centrifugal load enables the bellows to return to its original condition in sealing engagement with the walls of the tube.

Abstract: A specimen collection and separation assembly is provided. The assembly includes a tube having closure secured to the open top of the tube. The closure includes a section that is pierceable by a needle cannula for depositing a liquid specimen in the tube. A separator is disposed in the tube below the closure. The separator includes top and bottom ends. Portions of the separator adjacent the top define a resiliently deformable low density sealing plug dimensioned to sealingly engage the interior of the tube. A high density ring is integrally engaged with the seal and extends to the bottom of the separator. The relative densities and dimensions of the seal and the ring are selected to achieve an overall density between densities of the phases of liquid to be separated. The ring causes the seal to elongate in response to forces imposed by a centrifuge. The separator then will move to a position in the tube between the respective phases of the specimen being separated.

Abstract: A device and method is provided for separating components of a fluid sample. The device includes a plurality of constituents comprising a container, a liner in the container, a closure for the container and a composite element. The composite element is a seal plug with a density between the densities of the components of the fluid sample is releasably engaged with the container closure and with the liner. A needle cannula is used to deposit a fluid sample in the liner and the entire device is placed in a centrifuge. The centrifugal load causes the seal plug to separate from the closure and causes the liner to expand outwardly against the container. The seal plug migrates into the fluid sample and stabilizes between the densities of the components of the fluid sample. The liner will resiliently return to its initial configuration upon termination of centrifugal load such that the liner sealingly engages the seal plug and separates the components of the fluid sample.

Abstract: A device and method is provided for separating heavier and lighter fractions of a fluid sample. The device includes a plurality of constituents. The constituents include a container, a liner in the container and a composite element in the liner for separating the fractions of a fluid sample. The separator comprises a specific density at a target density range as defined by separable fluid components densities. A fluid sample is delivered to the liner and then the device is subjected to centrifugation whereby the centrifugal load causes the liner to deform and the composite element migrates into the fluid sample and stabilizes between the heavier and lighter fractions of the fluid sample. The liner will resiliently return to its initial configuration upon termination of the centrifugal load such that the liner sealingly engages the composite element and separates the heavier and lighter fractions of the fluid sample.

Abstract: A device and method for separating heavier and lighter fractions of a fluid sample. The device includes a flexible collapsible inner container disposed within a substantially rigid outer container. A closure seals the open top end of the outer container. A filter assembly is sealingly mounted to the open top end of the inner container. The filter assembly includes a filter that permits lighter fractions to pass therethrough, while substantially blocking the heavier fractions. The filter assembly further includes a filter support having a slit valve registered with the filter. The slit valve opens in response to fluid pressure created by the lighter fractions for permitting the lighter fractions to flow therethrough.

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: 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: A holding device for body fluid, tissue parts and tissue culture media includes a cylindrical holding container having a container wall with an inner surface defining an inner space, a first open end face having a diameter which is at least equal to the diameter of the inner space, and a second open end face having a conical sealing surface tapering inwardly in the direction of the inner space. A first closure device closes the first open end face and a second closure device closes the second end face. The second closure device includes a solid conical seal body 44 having a sealing surface conforming to the conical sealing surface of the second open end face and an outer end face of a larger diameter than that of an inner end face that faces the inner space. A retaining member 45 abuts the outer end face and is coupled to the outer container wall surface for holding the seal body in a sealing position in the second open end face.

Abstract: A method of dispensing gel for separation of the serum and coagulum portions of a blood sample in a blood collection tube is disclosed. The present invention of dispensing the gel preferably comprises utilizing a gel dispensing apparatus with a nozzle head having a plurality of openings. The gel dispensing apparatus dispenses either a continuous band of gel around the central portion of the collection tube or a plurality of discrete stripes that forms a circumferential pattern thereto. Once the gel is dispensed, the tube is ready for accepting a blood sample for eventual separation in a centrifuge where the dispensed gel will form a barrier that exhibits strong adhesive properties after separation of the blood sample has occurred.

Abstract: Device for the isolation of nucleic acids from a liquid sample by introducing the liquid into the device through an inlet opening and passage of the sample through a nucleic acid binding material and discharging of the resulting liquid through an outlet opening, wherein the nucleic acid binding material is inserted through the outlet opening during the manufacture of the device and the outlet opening is narrowed in order to hold the material. The device is particularly simple and reliable to manufacture but yet ensures that nucleic acids can be isolated without contamination.

Abstract: A collection device for plasma preparation for diagnostic assays. The device comprises a spray-dried anticoagulant formulation on the interior surface of the device and a thixotropic polymeric gel. The device is an improvement over commercially available devices which contain liquid anticoagulant formulations, for use in nucleic acid testing that employ amplifications technologies including, but not limited to, polymerase chain reaction (PCR), branched DNA (bDNA) and nucleic acid sequenced based amplification (NASBA).

Abstract: An assembly for collection of a sample of a body fluid from a subject's body of the present invention includes a hollow tube defining an axis with an open end and a closed end. The hollow tube defines a chamber therewithin for receiving a sample of a collected fluid from a subject. The tube has a resilient closure disposed in the open end to close the chamber and to form a seal capable of maintaining a pressure differential between atmospheric pressure and a pressure less than atmospheric pressure within the chamber. The chamber contains an aliquot of an aqueous additive for treating the fluid sample. The chamber also includes a matrix formed from a fibrous material having capillary spaces therein for absorbing the aliquot of the aqueous additive and an aliquot of a water immiscible liquid with a density greater than about 1.07 grams per milliliter to encapsulate the aqueous additive absorbed on the matrix.

Abstract: A method for rapid separation of serum or plasma from cells in a whole blood sample uses a cylindrical sample tube having longitudinally-extending internal ribs. A separation gel and the sample are introduced into the tube, and the tube is axially centrifuged so as to form concentric shells of cells, gel, and serum or plasma. After centrifugation is stopped, the serum or plasma collects in the tube by gravity flow and the cells and gel remain affixed to the walls and ribs of the tube.

Abstract: An auxiliary apparatus for sampling blood serum according to the invention comprises a disklike flattening member having a flat surface and capable of flattening a separation surface of a blood serum separating medium contained in a sample container by urging the flat surface against the separation surface, a mounting member having a cylindrical shaft for lowering the flattening member through the blood serum contained in the sample container to thereby mount the flattening member in the sample container such that the flat surface of the flattening member horizontally urges the separation surface of the blood serum separating medium, and means for securing a space which permits a sampling/dispensing tip capable of sampling and dispensing the blood serum, to be inserted into the sample container, by detaching the cylindrical shaft from the flattening member and taking the cylindrical shaft out of the sample container, after the flattening member is mounted in the sample container by the mounting member.

Abstract: A process for the production of a blood separating agent is disclosed which comprises supplying a mixture solution containing (a) a separation layer forming high molecular weight compound as the main component and (b) a thixotropy-providing agent selected from the group consisting of inorganic fine particles and organic gelling agents into a cylinder block of a homogenizer having the cylinder block equipped with a plunger capable of performing reciprocating movement and a valve body which is connected thereto and equipped with a valve member, a valve sheet and an impact ring, and applying a compressive shearing stress to the mixture in said homogenizer at such a temperature that viscosity of the solution becomes 1.times.10.sup.4 centipoises or less, thereby obtaining a blood separating agent in the form of a dispersion or a uniform gel. A blood separating agent having excellent storage stability can be obtained with improved productivity per unit time.

Abstract: An anticoagulant solution of sodium citrate for use in blood chemistry-related techniques and apparatus is disclosed. The anticoagulant solution should include an effective concentration of sodium citrate sufficient for preventing the coagulation of a sample of blood employed in the technique or added to the apparatus. The sodium citrate-based anticoagulant solution should have a pH ranging from above 6.0 to about 8.5 and a sodium citrate concentration preferably ranging from about 0.05M to about 0.2M.

Abstract: The present invention provides a serum separating device and an apparatus for use in serum separation which is capable of completely separating serum and clot during the separation of a blood sample into serum and clot by means of a centrifugal separation operation.

Abstract: A separator float has a generally cylindrical body and a water swellable band having a selected outer diameter fitted circumferentially around a portion of the generally cylindrical body. The water swellable band is made of a water swellable material so that upon being exposed to water the water swellable band swells to a greater outside diameter. The separator float is preferably used in a blood collection tube and has a specific gravity between specific gravities of a light phase and a heavy phase of the blood. After the blood has been collected and centrifuged the separator float moves to a position between the light phase and the heavy phase and the water swellable band is exposed to water in the blood causing the band to swell and create a seal. Thereafter, the serum or plasma as well as white blood cells, lymphocytes, monocytes and platelets can be removed from the blood collection tube.

Abstract: A polyester is provided which facilitates the separation of blood into light and heavy phases via centrifugation in a blood collection vessel. The polyester is useful as a component of a partitioning composition formulated to have appropriate specific gravity to be positioned intermediate the light and heavy blood phases during centrifugation. A partitioning composition including a polyester of the invention provides a particular advantage in blood collection vessels due to its lighter and more consistent coloration. The polyester composition can be prepared with relative ease compared to prior art polyesters useful in blood partitioning compositions.

Abstract: Methods and apparatus for separating red blood cells by density are described. Older red blood cells are more dense than younger ones. Certain changes in the physiology are recorded in changes in hemoglobin or the red blood cells. By assaying different aged red blood cells, one can determine the historical physiological changes over a period of many weeks. Improved separation of red blood cells is accomplished by using rigid capillary tubes having an inner surface which augments the density equilibrium of red blood cells and/or incrementally increasing the centrifugation forces, as well as by chemically treating red blood cells to improve their deformability.

Abstract: Gel formulations including a polydimethylsiloxane-polyethyleneoxide copolymer gelled with dibenzylidine sorbitol in the presence of water or alcohol, The gel formulations are useful for facilitating the separation of blood serum or plasma from the cellular portion of blood or as a thermoreversible shear sensitive substance.

Abstract: Gel formulations including a polydimethylsiloxane-polyethyleneoxide copolymer gelled with dibenzylidine sorbitol in the presence of water or alcohol. The gel formulations are useful for facilitating the separation of blood serum or plasma from the cellular portion of blood or as a thermoreversible shear sensitive substance.

Abstract: The invention provides a serum or plasma separating composition which comprises a cyclopentadiene resin, a viscosity adjusting agent and an organic gelling agent. The composition is characterized in that the cyclopentadiene resin is a liquid resin at a temperature of 25.degree. C., the viscosity adjusting agent being a liquid ester obtained from propionic acid, butyric acid, benzoic acid or phthalic acid, the organic gelling agent being a condensation product of sorbitol and an aromatic aldehyde, the composition containing 0.8 to 25 parts by weight of the viscosity adjusting agent and 0.03 to 0.9 part by weight of the organic gelling agent per 100 parts by weight of the cyclopentadiene resin. The composition forms a satisfactory separating layer even when subjected to a centrifugal separation operation at a set temperature of 4.degree. C.

Abstract: A serum:plasma separator is provided containing a tackifier having a softening point of 70.degree. to 150.degree. C. and a partition-forming material. The separator prevents hemocyte from remaining in a serum portion after blood separation and prevents migration of a component having a concentration gradient between clot and serum, even when separated blood components are stored as they are in place in a tube for the separation of blood, whereby correct examination results can be obtained. The serum:plasma separator hardly undergoes a form change at room temperature and under heat and hardly shows a viscosity change even after a long period of time. Further, the serum:plasma separator has an excellent thixotropic nature free from a change in temperature, excellent cohesion and excellent adhesion to a blood separation tube. There is also provided a tube for the separation of serum:plasma from clot;hemocyte, which contains the above serum:plasma separator.

Abstract: A process and method for preventing a separated material from interfering with the portion of a fluid to be sampled for use in a serum or plasma collection device including a gel material for partitioning and separating heavier and lighter phases of a fluid sample such as a blood sample. The device preferably includes a member such as a disc-shaped or ring-shaped member or a combination thereof to prevent the separated material from interfering with the sampling of the separated fluid sample. The member is preferably formed of hydrophobic and/or non-wetted material and has a specific gravity different from the specific gravity of the lighter phase. The process may also include a member which physically separates the separated material from the fluid to be sampled to allow the user to obtain an uncontaminated fluid sample.

Abstract: A method of partitioning a pre-selected phase of a sample of liquid having a plurality of phases of differing densities, a separation device and a tube containing the separation device. The sample of liquid is placed in a first chamber of a linear tube that is separated from a second chamber by a separation device. The separation device slidably engages the interior surface of the tube in an essentially fluid-tight manner and has an axial orifice on the longitudinal axis of the tube that is in fluid flow communication with a flow-restriction channel. The phases are ordered concentrically by rotating the tube around its longitudinal axis e.g. in an axial centrifuge. The volume of the first chamber is reduced by movement of the separation device within the tube, that phase of the liquid located axially within the first chamber flowing into the axial orifice and passing through the flow-restriction channel into the second chamber.

Abstract: A method of partitioning a pre-selected phase of a sample of liquid having a plurality of phases of differing densities, a separating element and a tube containing the separating element. The sample of liquid is placed in a first chamber of a tube that is separated from a second chamber by a separating element. The separating element slidably engages the interior surface of the tube in a substantially fluid-tight manner. A fluid passage is disposed through the separating element and includes an initially closed fluid passage. The phases are ordered by axial centrifugation wherein the tube is rotated about its longitudinal axis, the separating element is moved within the tube reducing the volume of the first chamber, a pre-selected phase of the liquid is forced from the first chamber through the fluid passage into a second chamber. The reduction of the volume of the first chamber is controlled using phase-separation information. The separator may also include a filter for filtering the fluid.

Abstract: In the performance of density gradient centrifugation back mixing after centrifugation is prevented by placing a snugly fitted layering insert within the vessel. The insert is capable of supporting the body of liquid dispersion to be centrifuged under regular gravity condition and enables bi-directional cross-flow during centrifugation. A small mesh filter plate may be placed on top of the layering insert.