Abstract: Apparatus for collecting, containing and separating a sample of blood. Disclosed is an apparatus for separating a pre-selected phase of a sample contained in an enclosed chamber, wherein said apparatus can be used with a separating means which rotates the chamber about a longitudinal axis of the chamber. In addition, separating means in which such an enclosed chamber is rotated about a longitudinal axis is described.

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 blood collection and separation system having multi-chamber collection assembly having a longitudinal axis. The assembly in a preferred embodiment is rotatable about its longitudinal axis and an alternate embodiment is rotatable about an axis parallel to its longitudinal axis. A porous separating body at one axial end of one chamber connects with a second chamber and allows flow of the lighter fraction of the blood from the one chamber to the other chamber during centrifugation, but blocks flow of the heavier fraction. Hydrostatic forces are created during centrifugation to cause flow of the lighter fraction through the body into the other chamber. Preferably the surface of the separating body which faces the first chamber slopes away the spinning axis so that centrifugal force tends to dislodge any particles of the heavier fraction which might be lodged on the surface. The assembly of the present invention affords handling of blood for testing or analysis without human exposure to the blood components.

Abstract: A method of partitioning a pre-selected phase of a sample of liquid having a plurality of phases of differing densities, and a tube. A sample of liquid is passed through a first end of a linear tube and into a first chamber of said tube. The first chamber is located at the first end of the tube and is separated from a second chamber located at a second opposed end of the tube by a separation device. The separation device slidably engages the interior surface of the tube in an essentially fluid-tight manner and has a flow-restriction orifice therein to permit fluid flow communication between the first and second chambers under the influence of force. The phases are then ordered within the tube using e.g. axial centrifugation. The volume of the first chamber is reduced by movement of the separation device within the tube, such that one phase of the liquid in the first chamber flows through the flow-restriction orifice and into the second chamber.

Abstract: 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 than the specific gravity of the lighter phase. The member also physically separates the separated material from the fluid to be sampled to allow the user to obtain an uncontaminated fluid sample.

Abstract: This invention relates to an apparatus used in a centrifugal separating step for sample preparation in the field of clinical chemistry. Especially, the invention relates to a separating apparatus used for isolating a serum fraction from a freshly isolated blood sample without contamination with a clot fraction. A serum separating apparatus according to the present invention is characterized by comprising an elastic body in the form of a cylindrical tube and a ball which can fitted to an opening of the elastic body and by positioning at a boundary of said fractions after the centrifugation.

Abstract: Device for measuring off of a volume of a flowable material, comprising a centrifugable reservoir provided with a bottom, side-walls and an entrance opposite the bottom, and an occludable aperture which is spaced between the bottom and entrance both when the aperture is open and when the aperture is closed. The aperture can be closed for collecting an overmeasure of the material in the reservoir pressed towards the bottom thereof during a first centrifuge run and can be opened for discharging the excess volume of the material during a second centrifuge run such that an exactly predetermined volume of the material is retained in the reservoir between the aperture and the bottom.

Abstract: 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 an affinity member such as a disc-shaped or ring-shaped member or a coating on the collection tube which has an affinity for the separated oil or degradation material from the gel material to prevent the separated material from interfering with the sampling of the separated fluid sample. The affinity member is preferably formed of hydrophobic and/or non-wetted material and has a specific gravity different than the specific gravity of the lighter phase.

Abstract: A blood collection tube includes a bottom and an open end that is hermetically sealed by a plug. A supporting film having an anticoagulant coated thereon is positioned within the tube. The anticoagulant-coated surface of the supporting member is provided with a large number of fine convexes.

Abstract: A modular reaction cassette has a fluid metering mechanism and valves for releasing fluid which are actuated by various centripetal acellerations generated in an automated patient analysis instrument having a variable speed rotor. Various geometries and sealant materials are used to select the rotational speed at which the sealant material yields to operate the metering device and release valves.

Abstract: A serum separation sealant containing 0.1 to 20 parts by weight of fine resin particles having an average particle size of 0.01 to 2 .mu.m and having an internal crosslinking density of 0.1 to 3 mmol/g and 100 parts by weight of a gelatinous material.

Abstract: A method of preparing neocytes and gerocytes in a closed blood bag system useful for the filtration of leukocytes from a red blood cell concentrate followed by the preparation and long term storage of neocytes and, preferably, gerocytes from the filtered concentrate. In very preferred embodiments, the system also provides containers for the expression of plasma and the preparation and long term storage of platelets.

Abstract: A liquid separating agent consisting essentially of a copolymer of an .alpha.-olefin having from 6 to 20 carbon atoms and a maleic acid diester with a copolymer composition (molar ratio) such that the maleic acid diester is more than 1.4 mols relative to 1 mol of the .alpha.-olefin, said copolymer having a molecular weight within a range of from 1,000 to 30,000.

Abstract: This invention relates to an assembly for centrifugally separating lymphocytes and monocytes from the heavier phases in samples of human blood utilizing a liquid density gradient medium. The particular inventive subject matter concerns the use of novel partition means initially separating the liquid density gradient medium from the sample of blood and designs for such partition means.

Abstract: Apparatus for partitioning a pre-selected phase of a sample of liquid, such as blood, having a plurality of phases of differing densities. Disclosed is an apparatus for separating a pre-selected phase of a sample contained in an enclosed chamber, wherein said apparatus can be used with a separating means which rotates the chamber about either a longitudinal axis of the chamber, or about an axis perpendicular to the longitudinal axis of the chamber and not passing through the chamber. In addition, separating means in which such an enclosed chamber is rotated about a longitudinal axis is described. Also disclosed is an apparatus for dispensing fluid from said enclosed chamber.

Abstract: Apparatus for collecting a sample of liquid, such as blood, having a plurality of phases of differing densities. Disclosed is an apparatus for collecting a sample in an enclosed chamber, wherein said apparatus can be used with a separating means which rotates the chamber about either a longitudinal axis of the chamber, or about an axis perpendicular to the longitudinal axis of the chamber and not passing through the chamber. In addition, said apparatus facilitates automated manipulation of the sample by providing formed features for: decreasing the gas permeability of said apparatus; clot activation of a blood sample contained within said apparatus; interconnection of a multiplicity of said apparatus; automated manipulation of said apparatus; protecting markings upon said apparatus; layering the construction of said apparatus; and, encoding of information upon said apparatus in both a tactile and visual manner. Also disclosed is an apparatus for dispensing fluid from said enclosed chamber.

Abstract: There is described a container for phase separation of at least two phases via centrifugation. Means are provided to prevent remixing, such means comprising porous mechanical means such as surfaces fixed in place and inclined at an angle to resist flow of the heavier phase upon removal of the lighter phase, such that remixing of the phases is prevented.

Abstract: A composition is provided for use, particularly in evacuated blood collection tubes, as a blood partitioning composition. The composition is useful in provididng cleaner serum or plasma samples for biochemical tests, including a wide range of drugs. The composition includes a balanced dual resin component which provides the desired hydrophobic property while simultaneously controlling viscosity and the specific gravity, which component is comprised of poly-alpha-pinene resin which provides good drug recovery but low density with a chlorinated hydrocarbon resin which provides the proper density level while maintaining the desired hydrophobic property of the resin blend. Thixotropic property is achieved by adding silica and network stabilizer in the composition.

Abstract: Apparatus and a method are described, wherein a coagulator accelerator is added to a container to achieve agglutination of blood cells when centrifuging whole blood, allowing the serum to be more easily poured off. The accelerator is selected from polymeric amines that are either polymerized amino acids or vinyl addition polymer amines, with a specified molecular weight range, the vinyl addition amines being selected to avoid lysing the blood cells.

Abstract: A device for separating and isolating heavier components from lighter components of blood mixtures after centrifugal separation, comprising a barrel for holding the blood mixture having slidably positioned therein an inner container for containing the lighter components, a one-way valve responsive to movement of the container within the barrel (a) for controlling the flow of the lighter components into the container, (b) for preventing the lighter components from re-entering the barrel from the container, and (c) for creating a vacuum to assist in drawing the blood mixture to be separated into the barrel, and a filter for filtering the lighter components during their entry into the inner container. The inner container includes an opening for access to the separated and isolated lighter components.

Abstract: An assembly for separating lymphocytes and monocytes from granulocytes in a sample of unseparated whole blood. A water insoluble, thixotropic gel-like substance, which is chemically inert to blood constituents is provided in a container. A fluid capable of altering blood cell densities and diameters is positioned above the surface of the water-insoluble thixotropic gel-like substance. Means for preventing the absorption of water by the thixotropic gel-like substance from the fluid and/or the sample of unseparated whole blood prior to separation are provided to substantially eliminate the influence of water absorption on the cell separation performance characteristics of said thixotropic gel-like substance.

Abstract: In a blood serum separator tube for separating blood into a lighter phase and a heavier phase, the thixotropic gel material initially disposed in the container lower end of the tube is protected from contact with any atmosphere contained in the tube, thus preventing separation of silicone oil from the silica-silicone fluid gel material during manufacture or storage. The gel material may be microencapsulated, or contained in a smaller number of larger capsules, or a single capsule. Alternatively, the gel material may be sealed in the tube under a curable elastomeric material, or under a water soluble material which dissolves upon contact with the blood being separated.

Abstract: This invention relates to an assembly for centrifugally separating lymphocytes and monocytes from the heavier phases in samples of human blood utilizing a liquid density gradient medium. The particular inventive subject matter concerns the use of novel partition means initially separating the liquid density gradient medium from the sample of blood and designs for such partition means.

Abstract: A device is provided for separating the components of a liquid sample by centrifugation by dividing that portion of the sample having a higher specific gravity from that portion having a lower specific gravity, by utilizing a dual component assemby arranged to move in an evacuated container into the area adjacent the two portions of the sample under centrifugal force. The assembly includes a substantially rigid core component which nests within a cup-shaped elastomeric component having a built-in spring action, and which components interact with each other to provide alternating dual seals and open flow paths in response to different pressure differentials on each side thereof.

Abstract: A blood separation device includes a collection tube containing a first layer of a thixotropic gel-like substance and a second layer of a newtonian gel-like substance which is positioned below the first layer. The first layer of the thixotropic substance is positioned between the second layer of the newtonian substance and a blood sample received by the tube, prior to centrifuging the tube, and acts as a barrier between the second layer and the blood sample to prevent intermixing of the second layer and the blood sample. The thixotropic gel-like substance of the first layer has a specific gravity which is greater than the newtonian gel-like substance of the second layer whereupon centrifugation of the tube, the first layer moves to a position below the second layer.

Abstract: A method and a device for separating the serum included in a certain volume of blood by way of centrifugation. The volume of blood is introduced into a test tube (1) in which a so-called separating body (5; 5') is also present, after which the test tube (1) is centrifugalized. The blood is separated into a heavy phase (11) containing red blood corpuscles and a light phase (12) containing serum or plasma. The separating body (5; 5') is given such a specific gravity that upon centrifugation it enters a position in the boundary layer between the heavy and the light phase (11 and 12, respectively).A (9; 9') stored in the separating body (5; 5') is moved out of this towards the heavy phase (11) and seals between separating body (5; 5') and test tube (1). When the mass (9; 9') is removed from the separating body (5; 5') a negative pressure will arise therein which is utilized to suck-up accumulated leukocytes and trombocytes into the separating body (5; 5').

Abstract: A disk shaped cassette for centrifugal fluid separation, particularly blood separation, and a drive system for high speed rotation of the cassette. The cassette is driven at speeds which permit very rapid separation of the blood in times on the order of seven (7) to twenty (20) seconds by an automated control. The cassette is supported by a flexible support coupling and mounting system that permits the entire rotating mass to spin about the center of mass unique to the particular cassette as filled. The cassette typically includes a peripheral collection chamber which may be either annular, lobed or channel shaped. A cassette enabled to hold plural separation tubes is also shown. A gel can be placed in the cassette with a density between the fluid components to separated and after centrifuging maintains the component separation that centrifuging creates.

Abstract: An assembly for separating lymphocytes and monocytes from granulocytes in a sample of unseparated whole blood. A water insoluble, thixotropic gel-like substance, which is chemically inert to blood constituents is provided in a container. A fluid capable of altering blood cell densities and diameters is positioned above the surface of the water-insoluble thixotropic gel-like substance. Means for preventing the absorption of water by the thixotropic gel-like substance from the fluid and/or the sample of unseparated whole blood prior to separation are provided to substantially eliminate the influence of water absorption on the cell separation performance characteristics of said thixotropic gel-like substance.

Abstract: A liquid separating agent consisting essentially of (A) a separating layer-forming material which is a polymeric oily substance selected from the group consisting of a copolymer of an .alpha.-olefin with an .alpha.,.beta.-unsaturated dicarboxylic acid diester and a copolymer of a styrene with an .alpha.,.beta. unsaturated dicarboxylic acid diester and (B) an organic gelling agent which is a condensation product of a benzaldehyde with a tetra- or higher hydric alcohol.

Abstract: A device is provided for separating the components of a liquid sample by centrifugation by dividing that portion of the sample having a higher specific gravity from that portion having a lower specific gravity, by utilizing a dual component assembly arranged to move in an evacuated container into the area adjacent the two portions of the sample under centrifugal force. The assembly includes a substantially rigid core component which nests within a cup-shaped elastomeric component, and which components interact with each other to provide alternating dual seals and open flow paths in response to different pressure differentials on each side thereof.

Abstract: This invention is directed to means for inhibiting the apparent shift in the buoyant density of and/or to restore any loss in the buoyant density of the granulocytic white blood cells in a sample of blood, thereby insuring the quality of the separation of lymphocytes and monocytes from granulocytes in a blood sample. The invention comprises contacting a blood sample with a hypertonic fluid containing a low molecular weight organic or inorganic ionic substance and/or with an isotonic or hypertonic fluid containing a high molecular weight organic substance which may contain organic molecules having a lipophilic substituent in their structures and/or with a culture medium for blood cells. An integral part of the invention is an improved blood separation tube utilizing a gel-like substance having a specific gravity between 1.060-1.065 g/cm.sup.3 to significantly enhance the purity of cell separation, while providing acceptable cell yields.

Abstract: An apparatus for separating blood is provided with a closed end and a thixotropic gel-like sealant with a specific gravity intermediate between the gravities of serum and clot phases. A cavity is formed on the upper surface of said sealant. The sealant consists essentially of an .alpha.-olefin-dimaleate copolymer having a viscosity from 10,000 to 120,000 c.p. (25.degree. C.), to which a viscosity-specific gravity adjusting agent is added to adjust the specific gravity to 1.035-1.055. The cavity is formed in such a size that diameter of the upper surface is from 0.15 to 0.7 times the inner diameter of the apparatus and its depth is from 0.13 to 0.65 times the thickness of said sealant.

Abstract: The present invention is directed to a method for separating mononuclear cells from other cells in a blood sample which is more rapid than the currently used density gradient material and which provides a better separation than methods utilizing thixotropic, gel-like material. In the method, a water soluble density gradient material is placed in a centrifuged tube. A water insoluble, thixotropic, gel-like substance is also placed in the container. A blood sample is placed in the container and the container is centrifuged for a time during which various components interchange positions and the gel-like substance forms a barrier between the mononuclear cells and the other cells of the blood sample.

Abstract: A blood collection device is provided with a phase partitioning device which includes a standpipe connected to a reservoir filled with a sealant material having a specific gravity intermediate the specific gravities of separated light and heavy phases of blood. Components of the heavy phase of blood enter the reservoir during phase separation and centrifugation to force sealant upwardly in the standpipe and out into the tube above the line of separation.

Abstract: A technique and receptacle for disinfecting biological fluids such as whole blood is described in which the disinfectant is prepositioned in a receptacle for biological fluids utilized for clinical evaluation in an amount which is sufficient to disinfect the fluid without interfering with subsequent clinical evaluation. The invention is specifically directed to disinfecting viral contaminants in blood by providing a closed container for the blood specimen which contains an amount of an aldehyde based disinfectant such as glutaraldehyde sufficient to destroy without otherwise affecting the integrity of the specimen for future evaluation. The amount of aldehyde based disinfectant positioned in the container is adjusted to provide an ultimate concentration in the blood specimen of aldehyde of about 0.1 to 2.5 weight percent and is buffered to a pH of about 7.2 to 8.5 percent preferably about 7.4.

Abstract: New and improved, liquid level adjusting and filtering device is provided, and is operable upon insertion into a container to automatically adjust the level of a liquid as contained in the container to a predetermined, precisely repeatable location, and to filter the thusly level-adjusted liquid. The device is particularly adapted for use in conjunction with test tube-like devices, in the nature of those marketed under the Trademark "Vacutainer" by the Becton-Dickinson Company of East Rutherford, NJ, containing whole blood samples which have been separated as by centrifugation into respective blood cell, buffy and blood serum layers; and is operable in that context to present blood serum samples to automated sample analysis systems at the same predetermined and precisely repeatable location relative to the aspirating probe means of such systems.

Abstract: An arrangement for placing a separating gel between two phases of different specific gravity located in a sample tube has a container (11) in which a separating gel (16) is accommodated. The container (11) which can be inserted into the sample tube up to the bottom thereof has a closed base (13) and a lid (14) at the top which can be displaced within the container in the manner of a piston. The lid is provided with at least one discharge opening (15) which is small relative to the area of the lid. The specific gravity of the lid (14) is greater than that of the separating gel (15) (FIG 3).

Abstract: Apparatus for separating or partitioning different density components of a liquid includes a liquid transfer pack composed of first and second flexible bags whose interiors are connected by tubing and a carrier for supporting the transfer pack. the carrier includes first and second sections defining first and second chambers for containing said first and second bags which sections can telescope between an extended condition wherein the volume of the second chamber is a maximum and a collapsed or retracted condition wherein the volume of the second chamber is a minimum. The two sections are biased toward their extended condition so that the first and second bags can be positioned in said chambers so that when the carrier and pack are spun at a selected high speed about an axis perpendicular to the carrier telescoping axis, the carrier sections will retract thereby maintaining the second bag in a collapsed condition in the second chamber minimum volume until the spinning slows to a selected lower speed.

Abstract: A mobile sewer and catch basin cleaning vehicle dislodges and removes debris in a conventional manner. The dislodged debris is then conveyed into a debris-receiving compartment where it undergoes a two-stage filtration process. The first stage removes the coarser debris from the reclaimed contaminated water. The second stage filters out the finer particulate debris by drawing such water through a finely filtered media surrounding a rotating drum. This filtered reclaimed water is then re-used in the cleaning operations. The extremely fine filtration media is continually cleaned by small amounts of clean water being applied at high pressure through nozzles designed to spray the entire media area as the drum rotates.

Abstract: A fluid collection device is provided which includes a container for receiving a liquid, such as blood, which is centrifugally separable into relatively light and heavy phases, and a phase partitioning device in the container. The partitioning device includes a bag filled with a thixotropic gel-like sealant having a specific gravity between the specific gravities of the separated light and heavy phases. During centrifugation, the components of the cellular phase cause collapse of the bag and the flow of sealant through an outlet in the bag. The sealant flows to the interface between the two phases during centrifugation and provides a barrier between the separated phases.

Abstract: An improved pre-evacuated blood sampling collection tube having two oppositely positioned rubber stoppers sealing the corresponding oppositely positioned open ends of the said cylindrical tube, and interposed within the said tube is a slideable perpendicularly placed filtration disc that filters and separates the cellular elements of the whole blood from its fluid counterpart during the process of centrifugation. One embodiment of the tube having a special structural extension baffle at one of the two sealing rubber stoppers, said structural extension found proximal to the puncturable entrant area of the blood specimen into the tube, acts as the structural baffle that prevents or curtails hymolysis of the red blood cells during the sudden onrush of blood from the blood source through the bore of the collection needle, and into the vacuum of the said collection tube.

Abstract: A serum and cell separating and dispensing device comprising an elongated tubular vessel partitioned throughout its length forming two distinct compartments containing vent orifices on either side. One opened end of the vessel is fitted with a resilient element containing a larger and smaller orifice which houses a small and large pore filter respectively. These orifices communicate with the two compartments respectively. At the opposite end of the vessel are two small tubular vessels extending from and communicating with the compartments formed by the partition. Blood drawn in an evacuated collection tube such as Becton Dickinson's vacutainer is centrifuged after clotting. The device is forced into the opened end of the collection tube and pressed downwardly. The resilient element forms an air trap by touching the inner wall of the collection tube and serum is forced through the orifices containing the filters.

Abstract: The present invention relates to apparatus and method for separating, by centrifugation, blood lymphocytes from other leukocytes in a blood sample. Small dense particles, either wetted or suspended in a physiological, hydrophilic medium, and a chemically inert hydrophobic barrier material are initially located in a suitable container. When the blood sample is added to the container, the particles are phagocytized by the monocytes and granulocytes, so as to increase their specific gravities. Upon centrifugation, the barrier material, whose specific gravity is only slightly greater than the specific gravity of the lymphocytes and less than the respective specific gravities of the phagocytic cells which have ingested particles and of the erythrocytes (red blood cells) in the blood sample, forms a rigid barrier therebetween, allowing harvesting of the lymphocytes, substantially free of contamination.

Abstract: In a serum separator, a sampling tube fits inside of a test tube. The sampling tube is provided with an elastomeric piston head at the lower end thereof having an annular lip to engage and form a seal with the inner sidewalls of the test tube. The upper side of the lip is provided with irregularities to break the seal between the lip and the test tube wall upon removal of the sampling tube from the test tube. A porous plastic filter body is mounted in a cavity in the piston head. The piston head defines a one-way valve in the form of a ball chamber containing a ball check. When the sampling tube is pushed into the test tube with a blood sample in the test tube, serum will pass through the filter body and valve into the interior of the sampling tube. The valve is constructed so that the serum cannot squirt toward the top of the sampling tube. When the sampling tube has been inserted, the valve will close.

Abstract: A blood-partitioning composition comprising a mixture of(1) a thixotropy-imparting agent,(2) a first viscous liquid material having strong interaction with the thixotropy-imparting agent, and(3) a second viscous liquid material having no strong interaction with the thixotropy-imparting agent and having good compatibility with the first viscous liquid material,said composition having a specific gravity at 20.degree. C. of from 1.03 to 1.08, and use of the composition in a method for partitioning a sample of blood.

Abstract: The invention is a device and a method for preparing serum from blood. The invention is used in conjunction with the centrifugal separation of serum from blood for filtering fibrin and other particulates from the separated serum and for partitioning the serum filtrate from unfiltered blood. During the first phase of centrifugation, a detent holds the serum preparator in check within the centripedal end of a tube containing the blood while the components of blood separate by sedimentation and backflow. Once all cellular components have sedimented to the pellet, the second phase of centrifugation begins and the sedimentation of the serum preparator is initiated by a triggering centrifugal force. During sedimentation, the serum preparator forces displaced serum to pass across a filter spanning an aperture through the serum preparator. The sedimentation velocity of the device and the rate of filtration are controlled by a brake on the serum preparator.

Abstract: An apparatus for separating blood is provided with a closed end and a thixotropic gel-like sealant with a specific gravity intermediate between the gravities of serum and clot phases. A cavity is formed on the upper surface of said sealant. The sealant consists essentially of an .alpha.-olefin-dimaleate copolymer having a viscosity from 10,000 to 120,000 c.p. (25.degree. C.), to which a viscosity-specific gravity adjusting agent is added to adjust the specific gravity to 1.035-1.055. The cavity is formed in such a size that diameter of the upper surface is from 0.15 to 0.7 times the inner diameter of the apparatus and its depth is from 0.13 to 0.65 times the thickness of said sealant.

Abstract: A blood collection device for collecting and separating whole blood into its relatively low and high density phases includes a collection container, and a housing having an enlongate passageway in the housing. Gel-like material having a specific gravity intermediate the specific gravities of the separated high and low density phases is disposed in the passageway. A piston having a specific gravity greater than that of the gel-like material is disposed in the passageway and sized to allow gel-like material to flow past it at a low flow rate and to retard the movement of the piston during centrifugation of the device. Means for preventing the flow of the gel-like material from the housing and toward the interface of the phases until the piston has moved out of the passageway is provided.

Abstract: A blood collection device for receiving whole blood adapted to be centrifuged into phases of lighter and heavier specific gravity includes a container with proximal and distal ends and a penetrable stopper at the proximal end. A separator assembly inside the container includes a receptacle with a thixotropic barrier material therein. An aperture in the receptacle faces toward the distal end of the container. The barrier material has a specific gravity intermediate the specific gravities of the lighter and heavier phases of blood and is adapted to flow under its own influence through the aperture during centrifugation. The barrier material then travels to a position intermediate the lighter and heavier phases of blood separated during centrifugation and adheres to the inside wall of the container to form a barrier.

Abstract: A method of preparing neocyte-enriched blood is disclosed wherein a contained sample of whole blood is centrifuged at high speed so as to distribute the blood components in said chamber along a density continuum. Following the high-speed centrifuging step, the blood components in the first chamber are partitioned by transferring those components beyond a selected partition line in the first chamber from the spin axis to a second chamber so that the blood components in the first and second chambers can be used independently. Apparatus for effecting the separation and partitioning of the blood in a completely sterile environment is also disclosed.