Abstract: Method and apparatus for partitioning a pre-selected phase of a sample of liquid, such as blood, having a plurality of phases of differing densities the method comprising the steps of introducing a sample into a chamber of constant cross-sectional shape and a volume greater than that of the sample, ordering the phases of the sample concentrically by rotating the chamber about its longitudinal axis, reducing the volume of the chamber in response to a separation control signal, removing a portion of the separated sample in order of phase, deriving information about the portion of the sample being removed from the chamber and modifying the separation control signal in response to the derived information.

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: Sedimentation classification of particulate material in liquid dispersion. The dispersion is centrifuged in a tubular vessel comprising at least two neighboring compartments communicating via at least one opening which may be capillary. The lowermost compartment has a sealed bottom and the uppermost has an open upper end. Upon completion of the centrifugation a liquid fraction with dispersed particulate material is decanted from the uppermost compartment. Useful products may also be recovered from other compartments.

Abstract: A cassette has a foraminous lower portion which is shaped to receive a button or pellet of agar and is capable of being placed in the bottom of a fluid container for use in a centrifuge. After the cassette portion is placed in the container, a fluid containing cells is poured in the container which is then centrifuged causing the cells to adhere to the agar. The fluid is then poured out, the cassette lower portion removed from the container and an upper foraminous cassette portion is used to cover the lower portion and enclose the agar with adhered cells.

Abstract: An apparatus and method of separating a component from a collected quantity of fluid. The apparatus includes a dual member centrifuge and an associated fluid flow transfer set. The transfer set has a collection container in which a quantity of fluid can be initially accumulated. The collection container is formed as a disk-shaped plastic member with an elongated generally radially extending barrier member formed therein. A component collection container is in fluid flow communication with the disk-shaped container. The method provides for centrifugation of the collection container in the dual member centrifuge thereby separating out the selected fluid component. The component can then be pumped out of the collection container into the component accumulation container. The residual fluid can be sealed in the collection container for later use. The component collection container can be separated and sealed also for later use.

Abstract: A centrifuge tube is used to hold a mixture of several constituents, and also contains a generally cylindrical float. The float settles, after centrifugation, into the zone occupied by the constituent whose volume is to be measured. The constituent layer will settle, after centrifugation, into the annular space between the tube bore and the outside of the float, and will be expanded axially due to the restricted volume of the annular space. The degree of expansion is dependent upon the respective sizes of the float O.D. and the tube bore ID, both of which must be closely controlled for accurate results. A known volume of a control material is placed in the tube to settle into the annular space during centrifugation in an area thereof outside of the constituent layer zone. The length of the band of the control material is measured after centrifugation and is compared to a known length which will result if the annular space is of the proper target volume.

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: Hydroxyalkyl celluloses are useful as sedimenting agents in the non-destructive separation of red and white blood cells. Intact WBC recovery is higher than with conventional methods. The white blood cells may be used in interferon production.

Abstract: A process is provided which proposes that the kinematic viscosity of the lacquer sludge is reduced to less than 100 cSt by adding to the sludge up to 50% by volume solvent and/or by heating it up to 60.degree. C., and that the content of solids of the liquefied lacquer sludge is reduced to less than 3% by volume first in a decanting centrifuge with a centrifugal acceleration of up to 4,000 g, and subsequently in a centrifugal separator with a centrifugal acceleration of up to 14,000 g.

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 device is described for preparing a standardized concentration of washed particles suspended in a fluid. The preferred method is directed to the preparation from whole blood specimens of a standardized concentration of washed red cells in isotonic solution using a device comprising a test tube formed at the bottom end with a nipple-like receptacle having a predetermined volumetric capacity. Whole blood is mixed with isotonic solution in the device which is then centrifuged causing the red cells to be first washed and then packed into the receptacle. The liquid contents of the device are then decanted without disturbing the packed red cells. Thereafter, the red cells are reconstituted to the desired concentration by adding isotonic solution to a predetermined level in the tube and mixing the cells into the isotonic solution.

Abstract: Method of separating blood, in particular for recovering thrombocytes and/or leucocytes, the whole blood coming from the donor being separated in a separation means of a centrifuge into an erythrocyte fraction, cell-poor plasma, a thrombocyte fraction and/or possibly a leucocyte fraction, the separated fractions of the blood being discharged via a flexible tubing system of discharge lines out of the separation chambers of the centrifuge and constantly predetermined amounts of separated cell-poor plasma returned to the whole blood to be separated or to the already separated erythrocytes in the separation chamber, and a separation apparatus for carrying out the method comprising a separator having one or more separating chambers connected together and a flexible tubing system which includes a supply line (1, 2) for the supply of the whole blood to be separated to the separator and discharge lines each for the separate discharge of the erythrocyte fraction (10), the cell-poor plasma (3, 5), the thrombocyte fract

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: In order to provide for a sharply defined line of demarcation between red cells and granulocytes in a centrifuged blood sample, the blood sample is drawn into a capillary tube. The bottom of the capillary tube is capped and the blood sample is centrifuged for a time sufficient to layer the blood sample in its constituent blood cell types. The capillary tube is then removed from the centrifuge and the top of the capillary tube is capped. The tube is then placed in the centrifuge inverted from its original orientation whereupon the sample is centrifuged again. Abnormally light red cells are thus trapped towards the bottom of the red cell column whereupon they cannot float up into the granulocyte band.

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: A particle washing system and method of use provides for the placement of the fluid containing the desired particles within an inner tube having near the bottom thereof an orifice plugged with a material for sealing the particulate containing fluid from a wash fluid under forces substantially equal to 1G. The inner tube is positioned within an outer tube which contains a wash fluid having a density at least equal to that of the particle containing solution but less than that of the particles. Application of centrifugal force, substantially greater than 1G, and directed toward the bottom of the outer tube, causes the sealing material to be dislodged thereby permitting the particles to move through the orifice and through the outer solution. Thus the particles are collected from the inner solution, washed by the outer solution, and pelleted at the bottom of the outer tube.

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: Method and apparatus for separating and measuring the amount of the glycosylated hemoglobin fractions in a blood sample. The method and apparatus provide a means for lysing sample red blood cells and, in the same container, separating the glycosylated hemoglobin fractions from the other residual hemoglobin fractions through the utilization of a polymeric material.

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 silica-silicone fluid gel, the properties of which are not significantly affected by sterilizing doses of radiation, is prepared by reaction of a silicone fluid having a narrow viscosity distribution with a filler material and a network former at or below about 120.degree. C.

Abstract: A method to facilitate the analysis of uncoagulated blood, for example freshly drawn blood or heparin blood, wherein the blood is filled into a test tube of plastic and a porous, elastic body in which one or more ballast element optionally are embedded, is placed in the upper layer of the blood and the blood is centrifuged such that the body in friction contact with the inner surface of the test tube is pressed through the blood, wherein the body or bodies are of glass or another suitable material with a surface whose characteristics correspond to those of glass, and where in addition there is used an overlying layer of small beads or other particles whose specific gravity is adapted in such a way that the beads after the centrifugation are embedded in the fibrin layer as reinforcement, and further wherein the two features may be combined by utilzing only the described small beads. A means for carrying out the method is also described.

Abstract: The rheological properties of thixotropic, gel-like compositions employed in blood separation tubes are controlled by incorporating in the composition up to about five percent by weight, based on the amount of composition, of a disilazane.

Abstract: A liquid separating agent used for fractionating a liquid such as blood that contains more than one component of different specific gravities, by separating a specific component from other components by means of the specific gravity difference is characterized by consisting of as the main component an .alpha.-olefin-dialkylmaleate copolymer having a viscosity between 10,000 and 80,000 cp (at 25.degree. C.); a viscosity and specific gravity adjusting agent such as silica or clay; and wax, a surfactant and so on as required.

Abstract: A blood collection tube is provided with a blood phase partitioning device disposed in the upper portion or adjacent the low density blood phase end of the tube. The device carries blood phase barrier gel-like material which flows through a restricted orifice in the device to meter or reduce the flow rate of the material into the blood during centrifugation to suitably delay the formation of the complete phase barrier until complete blood phase separation has taken place.

Abstract: A rapid one-step density separation method for separating and purifying whole blood into mononuclear and polymorphonuclear leucocyte and erythrocyte fractions wherein use is made of a separating medium consisting of a single aqueous solution of a high molecular weight sucrose or glucose polymer, and a water soluble metrizoate or diatrizoate compound, the density of the solution being greater than 1.095 gm/ml at room temperature and the concentration of the sucrose or glucose polymer lying in the range of 5 to 10% (based on weight/total volume of solution).

Abstract: A fluid collection device is provided which includes a container for receiving a liquid, such as blood, that is centrifugally separable into relatively light and heavy phases, and a phase partitioning device in the container. The partitioning device includes a thixotropic gel-like material adjacent one end of the container having a specific gravity between the specific gravities of the light and heavy phases, and a piston member having an outlet in communication with the sealant so that during centrifugation of the device, centrifugal forces cause the piston to pressurize the sealant and force the sealant through the outlet toward the interface of the phases with sealant forming a partition between the separated phases.

Abstract: A method for determining the thickness of a charge wall being formed against the side wall of a rotating centrifugal basket by flow of charge material into the basket comprises the steps of establishing a capacitance across the charge space of the basket and sensing any change of capacitance which results as the charge wall thickness is increased by the flow. An apparatus for determining the thickness of the charge wall formed against the side wall of the centrifugal basket includes an electrically conductive plate disposed in the basket inwardly of the charge space and a source of voltage for establishing an electric field between the plate and the side wall. A capacitance sensor senses any change in the established capacitance resulting from the formation of a charge wall in the basket.