Abstract: A chamber for use in a rotating field to separate blood components. An inlet port near one end of the chamber introduces blood into the chamber for flow circumferentially about the rotational axis toward the opposite end of the chamber for separation into at least one blood component. At least one outlet port is juxtaposed next to the inlet port near the one end of the chamber for conveying one separated blood component from the channel. The chamber directs the one separated blood component to a collection region near the opposite end of the chamber. An enclosed interior collection passage within the channel leads from the collection region and directs the one collected component to the outlet port for transport from the chamber.

Abstract: A system compact enough to be located entirely beside the donor's chair, and able to process the blood while the donor is still resting in the chair after having donated the blood. The separated blood components (plasma and red blood cells) may be stored in their individual optimum environments immediately after the whole blood is drawn, and the blood does not need to be transported back to a separation laboratory for processing. The system includes a needle (72) (or other cannula-like device) for insertion into a vein of the donor and drawing whole blood therethrough, a rotor (2a) for holding the blood after it is drawn, and a motor (50) for spinning the rotor so as to cause the blood to separate into components, for example, plasma and red blood cells. The system also provides for a container for collecting a separated component.

Abstract: The present invention relates to methods of enriching breast tumor cells from a patient's body fluids. In particular, it relates to the use of a cell-trap centrifugation tube containing a specific density gradient solution adjusted to a specific density to enrich for breast tumor cells from a cell mixture. The tube allows the desired cell population to be collected by decantation after centrifugation to minimize cell loss and maximize efficiency. In addition, the method can be further simplified by density-adjusted cell sorting which uses cell type-specific binding agents such as antibodies and lectins linked to carrier particles to impart a different density to the non-tumor or tumor cell populations allowing the breast tumor cells to be separated from the non-tumor cells in a more convenient manner.

Abstract: The present invention relates to methods of enriching fetal cells from maternal body fluids. In particular, it relates to the use of a cell-trap centrifugation tube containing a gradient solution adjusted to a specific density to enrich for fetal nucleated red blood cells from maternal blood. The tube allows the desired cell population to be collected by decantation after centrifugation to minimize cell loss and maximize efficiency. In addition, the method can be further simplified by density-adjusted cell sorting which uses cell type-specific binding agents such as antibodies and lectins linked to carrier particles to impart a different density to undesired cell populations allowing the fetal cells to be separated during centrifugation in a more convenient manner. The rapid fetal cell enrichment method described herein has a wide range of applications, including but not limited to, gender determination and prenatal diagnosis of genetic diseases without the use of invasive procedures.

Abstract: Systems and methods for separating blood rotate a separation chamber about a rotational axis to create within the chamber a low-G wall radially close to the axis and a high-G wall spaced radially further from the axis than the low-G wall. The systems and methods introduce whole blood into an inlet region of the chamber during its rotation through a reduced passage. The reduced passage restricts whole blood flow, thereby causing more uniform perfusion of whole blood in the inlet. Separation of red blood cells begins within the inlet region toward the high-G wall. This creates a flow of plasma that moves within the inlet region radially toward the low-G wall and elutes platelets into suspension. The systems and methods direct the radial flow of plasma and eluted platelets to an outlet in the inlet region for transport from the chamber.

Abstract: A blood sample is gravimetrically separated into its heavier and lighter phases by centrifugation in a tube. The phases are separated by a disc which has a center of buoyancy and a center of mass that are spaced apart from each other along the axis of symmetry of the disc. The diameter of the disc is slightly larger than the bore diameter of the tube. The disc is initially positioned in the tube with its axis of symmetry perpendicular to the axis of the tube so that blood drawn into the tube can readily pass by the disc. Upon centrifugation, the disc will tumble through a 90.degree. angle so that the axis of symmetry of the disc will be coincidental with the axis of the tube. Once the disc has tumbled in the sample, the ongoing centrifugal forces will cause a stretching of the disc along its axis of symmetry thereby decreasing the diameter of the disc.

Abstract: An apparatus and method for transferring a centrifugally separated component in a liquid contained in a flexible bag is disclosed. The apparatus is composed of a centrifugal container for accommodating flexible blood collecting bag filled with blood, and a pushing mechanism for pushing the blood collecting bag. The pushing mechanism is composed of a pair of rollers for pushing a soft material part of the cylindrical portion of the centrifugal container from opposite directions in such a manner that the soft material part is deformed inwardly to project inside the centrifugal container and increase inner pressure of the flexible bag to transfer separated component out of the flexible bag. According to the apparatus and method, the yield for collecting the separated component obtained by centrifugal separation can be increased, and the time required for collection can be decreased.

Abstract: Blood processing systems and methods create dynamic vortex flow conditions within the processing chamber by conveying blood into a separation path that extends circumferentially about the rotational axis along an entry path that extends generally parallel to the rotational axis. The vortex flow conditions perfuse blood into the separation path for separation into component parts. The systems and methods confine the vortex flow pattern along the entry path by reducing the radial width of the entry path.

Abstract: Method of treatment by centrifuging of a liquid packaged in flexible-walled bags connected to at least one filter. According to the method, the filter (2) is placed in the middle of the confinement space (5, 5a) such that the large faces of the filter (2) are parallel to the centrifuging axis (3), and bags (1) are placed on either side of said filter (2) so that they are in contact with the latter.

Abstract: The present invention provides lyophilized reagent spheres comprising reagents suitable for analysis of biological samples, in particular analysis of blood samples in centrifugal analyzers. Also provided are diluents which are conveniently used in such analyzers.

Abstract: A system for collecting and processing donated blood comprises a first porous medium interposed between a blood collection bag and a satellite bag and a second porous medium interposed between the blood collection bag and another satellite bag. The porous media are leucocyte depletion media. The system may also include one or more of the following: a red cell barrier medium, a separation medium, a gas inlet, and a gas outlet. The system can be used to centrifuge whole blood into one or more components, and includes a means for protecting the system during centrifugation.

Abstract: Methods and apparatus are disclosed for separating and collecting blood fractions or components such as platelets. A first anticoagulant solution is added to whole blood, which is then separated into platelet-rich plasma and red cells. A second anticoagulant is added to the platelet rich plasma, which is then separated into platelet-poor plasma and platelet concentrate. The rate of red cell sedimentation is increased and the time of the separation/collection procedure may be reduced when the pH of the first anticoagulant is greater than approximately 6.0.

Abstract: A method for the continuous conditioning of a cell suspension, more particularly whole blood, in order to obtain an erythrocyte concentrate which is returned to the patient by autotransfusion. In accordance with the invention there are three treatment stages, that is to say sedimentation of the cell suspension, the addition of washing solution to the cell concentrate and renewed sedimentation and separation of the washing solution.

Abstract: In a process of separating a liquid sample having phase portions of different densities by centrifugal separation, a phase separator container is employed. The phase separator container comprises a housing having concentric inner and outer cylindrical walls defining a longitudinal axis and a top wall and further a piston body constituting a bottom wall of the housing. The piston body defines together with the outer cylindrical wall, the inner cylindrical wall and the top wall, an annular chamber for receiving the liquid sample. The piston body is displaceable within the annular chamber for draining a phase portion separated from the liquid sample through a drain conduit means communicating with the annular chamber. The phase separation chamber further comprises a reaction chamber to which the phase portions exposed from the annular chamber is processed.

Abstract: The present invention provides centrifugal rotors for delivering a liquid, typically a biological sample such as diluted plasma, to an unvented chamber in the rotor through an unmodified inlet channel. The unvented chamber is typically a cuvette comprising reagents necessary for analysis of a biological sample. The unmodified inlet channels are sized such that, as the rotor spins, gas escapes from the chamber through the inlet channel as the liquid enters the chamber through the inlet channel. The primary feature which allows the air to escape from the unvented chamber is that the cross sectional area of the inlet channel is greater than the cross sectional area of the liquid flowing through it.

Abstract: An inexpensive device with a disposable cartridge for preparing tissue sealant is disclosed. The device is particularly applicable to star preparation of autologous tissue sealant. A method of sealing tissue in which the tissue sealant is applied immediately after mixing platelet-rich plasma concentrate (from the device) with a solution of calcium and thrombin is also disclosed. Preparation in the operating room of 5 cc sealant from 50 cc patient blood requires less than 15 minutes and only one simple operator step. There is no risk of tracking error because processing can be done in the operating room. Chemicals added may be limited to anticoagulant (e.g., citrate) and calcium chloride. The disposable cartridge may fit in the palm of the hand and is hermetically sealed to eliminate possible exposure to patient blood and ensure sterility. Adhesive and tensile strengths are comparable or superior to pooled blood fibrin sealants made with precipitation methods.

Abstract: Systems and methods for separating mono nuclear cells from whole blood rotate a separation chamber about a rotational axis. The systems and methods introduce whole blood into a first region of the chamber during its rotation to separate the whole blood into a plasma constituent, red blood cells, and an interface between the red blood cells and the plasma constituent. The interface carries mono nuclear cells. While conveying whole blood into the first region, the systems and methods collect the plasma constituent in the first region, while also collecting the red blood cells in a second region of the chamber spaced from the inlet region. The systems and methods create, while conveying whole blood into the inlet region, a back flow of plasma constituent along the interface from the second region toward the inlet region. This back flow of plasma maintains a high-relative hematocrit in the second region and a low-relative hematocrit in the inlet region.

Abstract: A method for separating blood into its components and individually storing same is provided. The method has the steps of: providing a container having a body with at least a first and second chamber. Selective fluid communication is also possible between the first and second chamber, and a tube is in fluid communication with the first chamber. The method also has the steps of: passing the blood into the first chamber through the tube; centrifuging the container to separate the blood into plasma, red blood cells and buffy coat within the first chamber; and expressing a portion of the centrifuged blood into the second chamber. In another embodiment, the method for storing blood has the steps of: providing a container with a body having three chambers.

Abstract: The present invention provides a method and device for detecting the presence of binding ligands, especially blood group antigens or antibodies thereto, which utilize a matrix of substantially noncompressable microparticles, which matrix provides superior performance in allowing movement of nonagglutinated reactants, especially red blood cells, while constraining, preferably in a so-called "band formation" agglutinated reactants, especially red blood cells.

Abstract: Systems and methods are provided for reducing the number of leukocytes in cellular products like platelets collected in an on line or continuous blood separation processes. The systems and methods reduce the number of leukocytes from a cellular suspension before its separation into a cellular-rich concentration. This leads to effective and efficient leukocyte removal and a high quality blood product suited for therapeutic use, with and without long term storage.

Abstract: Disclosed is a method for separating a blood material into blood components by centrifugation, wherein when a multiple blood bag unit including a plurality of flexible blood bags (at least one of the flexible blood bags containing a blood material) liquid-tightly connected to at least one leukocyte-removing filter device through flexible tubes in a predetermined order is accommodated in a centrifuge bucket, at least the blood material-containing flexible blood bag or bags are inserted in the centrifuge bucket while placing at least the leukocyte-removing filter device outside of the centrifuge bucket, wherein the leukocyte-removing filter device is directly or indirectly secured relative to the rotor and a center of the filter device is located at a distance from an axis of the rotation shaft which is smaller than a distance between a pivotal axis of the turning of the centrifuge bucket and an axis of the rotation shaft at a portion thereof which has the rotor connected thereto.

Abstract: Methods and systems for processing a biological fluid and treating a separated component of the biological fluid are disclosed.

Abstract: Disclosed is a leukocyte-removing filter device comprising (a) a casing having an inlet for blood and an outlet for leukocyte-removed blood, which are both located in a top portion of the casing, and (b) a filter medium disposed in the casing so as to divide the internal space of the casing into an inlet-side chamber communicated with the inlet and an outlet-side chamber communicated the outlet.

Abstract: A method and apparatus are provided for removing liquids from biological waste by the employment of centrifugal force to separate the liquid from the biological waste particulate and into a container separate from a biological waste container, permitting the dried biological waste and removed liquid to be separately and conveniently disposed of. Preferably, a rotatable drum can be rotatably supported within an outer liquid-tight drum, and a disposable porous container, such as a bag made of porous material, can be placed within the rotatable foraminous drum. Biological waste can be placed within the porous, disposable container within the rotatable drum, and the rotatable drum can be rotated at a rate of rotation sufficient to substantially transfer unabsorbed liquid from the biological waste through the disposable porous container and the openings in the foraminous inner drum to the outer liquid-tight collection drum. The collected liquids may be disposed of by pumping them into a sanitary sewer.

Abstract: Systems and methods for separating a suspension of plasma and platelets from whole blood rotate a chamber about an axis to create within the chamber a low-G zone radially close to the axis and a high-G zone spaced radially further from the axis than the low-G zone. The systems and methods introduce whole blood into an inlet region of the chamber to initiate separation of red blood cells toward the high-G zone of the inlet region. This creates a strong flow of plasma that moves radially toward the low-G zone of the inlet region and elutes platelets into suspension with it. The systems and methods direct the radial flow of plasma and eluted platelets within the inlet region to a port in the inlet region for transport out of the chamber. The systems and methods also drag the interface into this radial plasma flow, eluting even the largest of platelets into suspension for collection.

Abstract: A composite of interconnected bags comprises a blood collecting bag, a preserving liquid bag, and a blood plasma bag. The interior of the bag body of the blood collecting bag is divided by a partition strip into an empty space and an empty space of the shape of a strip, with the two empty spaces mutually communicating near the end part of the partition strip. The blood collected in the blood collecting bag is centrifuged. The upper layer of blood plasma resulting from the centrifugation is discharged via a tube to the blood plasma bag. Then, the erythrocyte preserving liquid in the preserving liquid bag is advanced through the tube, the empty space, and a connecting part and added upwardly from below to the concentrated erythrocyte left behind the empty space. The erythrocyte preserving liquid, without being stirred, is allowed to ascend and mingle with the concentrated erythrocyte with the elapse of time.

Abstract: Useful information about a subject's level of systemic inflammation is obtained by quantitatively measuring the amount of fibrinogen and the hematocrit and or hemoglobin in the subject's whole blood. The fibrinogen measurement, when combined with an hematocrit or hemoglobin measurement, provides a systemic Inflammation Index value for the donor. The method is not affected by blood variables which are not related to the presence of inflammation, which blood variables are known to invalidate an erythrocyte sedimentation rate, which is the most frequently used blood test for detecting systemic inflammation in humans.

Abstract: An apheresis apparatus and method is disclosed for increasing the purity and yield of platelets separated from donated whole blood in a centrifuge. The whole blood in the centrifuge is diluted by recirculating fluid, such as plasma or saline, at a first flow rate, to mix with further withdrawn whole blood prior to entering the centrifuge. As plasma is collected, it is recirculated through the centrifuge at a second flow rate to further improve the separation between the intermediate density components, i.e., platelets and white blood cells in the "buffy coat." The plasma is then recirculated through the centrifuge at a third flow rate and platelets are displaced out of the centrifuge while the plasma is recirculating through the centrifuge at the third flow rate.

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: A density gradient medium for the isolation and enrichment of rare cells, including fetal nucleated erythrocytes from a peripheral blood sample is described. The medium comprises a colloidal density gradient medium dispersed in a meltable gel. In one aspect of the invention, the density gradient medium is hypertonic to facilitate separation of maternal red blood cells from fetal blood cells.

Abstract: The present invention relates to methods of enriching hematopoietic progenitor cells from body fluids. In particular, it relates to the use of a cell-trap centrifugation tube containing a gradient solution adjusted to a specific density to enrich for CD34.sup.+ cells from apheresed blood. The tube allows the desired cell population to be collected by decantation after centrifugation to minimize cell loss and maximize efficiency. In addition, the method can be further simplified by density-adjusted cell sorting which uses cell type-specific binding agents such as antibodies and lectins linked to carrier particles to impart a different density to undesired cell populations allowing the progenitor cells to be separated during centrifugation in a more convenient manner.

Abstract: Methods and devices for treating transition zone material are disclosed. Transition zone material is processed to form a supernatant layer which includes platelets and a sediment layer which includes red blood cells, and the supernatant layer is separated from the sediment layer by passing the supernatant layer through a porous medium. Once the supernatant layer has been separated from the sediment layer, gas may be separated from the supernatant layer.

Abstract: Disclosed is a method for separating a blood material into leukocyte-removed blood component products, which comprises providing a multiple blood bag system comprising a primary bag containing a blood material, a leukocyte-removing filter device comprising a flat casing, and at least one satellite bag, and centrifuging the blood material using a centrifuge cup having the multiple blood bag system accommodated therein, to thereby separate the blood material into blood components, wherein the centrifugation is performed with the filter device being held by a filter device holder having a substantially flat dimension which is disposed in a centrifuge cup so as to extend in a direction perpendicular to an inner bottom floor of the centrifuge cup, and wherein the filter device holder has a recess and the filter device is received by the recess in a manner such that a flat surface of the flat casing of the filter device is perpendicular to the inner bottom floor of the centrifuge cup.

Abstract: A tube for collection, separation and dispensation of a two-phase fluid is provided with a elongated rigid tubular container having a fluid entry end a closable end and a float. The float retained within the tubular container is positioned between the light phase and the heavy phase of the fluid on centrifugation thereby separating the two phases. In dispensing the light phase, the float moves to and engages the fluid entry end thereby preventing the heavy phase from escaping out of the tube.

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 for isolating and enriching rare cells, including fetal nucleated erythrocytes from a peripheral blood sample is described. The method includes two centrifugation steps, the first a bulk separation step to enrich erythrocytes from other blood components. The second centrifugation comprises a colloidal density gradient medium dispersed in a hypertonic meltable gel. In one aspect of the invention, maternal erythrocytes may be hemolyzed prior to the second density gradient centrifugation to provide additional enrichment for fetal nucleated erythrocytes.

Abstract: Systems and methods resuspend cellular-rich concentrates of blood by rocking the separation chamber to create variable agitation forces within the separation chamber. The systems and methods also add resuspension fluids to aid the resuspension.

Abstract: Disclosed is an improved method for hemoglobin purification utilizing a novel two-step dual-aqueous-phase extraction technique to separate hemoglobin from red cell membrane stroma and other protein contaminants. In the first step, a first dual-aqueous-phase liquid system is prepared which comprises an upper aqueous phase containing polyethylene glycol in water and a lower aqueous phase containing a phosphate buffer at a pH of about 10. In the second step, a second dual-aqueous-phase liquid system is prepared which comprises an upper aqueous phase, which contains the polyethylene glycol phase containing the hemoglobin extracted in the first step, and a lower aqueous phase containing a new phosphate buffer at a pH of less than 7.5. After the second extraction step, purified hemoglobin solution can then be obtained by removing the phosphate salt and the minute amounts of polyethylene glycol contained in the lower phase.

Abstract: The present invention provides an apheresis apparatus and method for separating blood. A phlebotomy needle draws anticoagulated whole blood from a donor into a separation chamber. The separation chamber separates plasma from higher density blood components. The plasma is displaced to a plasma collection bag. The separation process is terminated and the higher density blood components remaining in the separation chamber are diluted with saline solution and are returned to the donor via the phlebotomy needle. Anticoagulated whole blood is drawn again from the donor into the separation chamber. The separation chamber again separates plasma from higher density blood components in the separation chamber. The separation process is then terminated and the donor is disconnected. The higher density blood components remaining in the separation chamber are displaced to a bag for collecting higher density blood components and is rejuvenated with additive solution.

Abstract: A centrifuge for the separation of blood into its components, especially a single-needle centrifuge, in which, in a collecting cycle, erythrocytes and plasma are passed through a centrifuge separation chamber and temporarily stored in a storage container and, in a recirculation cycle, the blood components temporarily stored in the storage container are passed through the separation chamber again and then returned to the patient.

Abstract: Systems and methods for separating a suspension of plasma and platelets from whole blood rotate a chamber about an axis to create within the chamber a low-G zone radially close to the axis and a high-G zone spaced radially further from the axis than the low-G zone. The systems and methods introduce whole blood into an inlet region of the chamber to initiate separation of red blood cells toward the high-G zone of the inlet region. This creates a strong flow of plasma that moves radially toward the low-G zone of the inlet region and elutes platelets into suspension with it. The systems and methods direct the radial flow of plasma and eluted platelets within the inlet region to a port in the inlet region for transport out of the chamber. The systems and methods also drag the interface into this radial plasma flow, eluting even the largest of platelets into suspension for collection.

Abstract: A method and apparatus for the multiple passage of fluids through a treatment unit (e.g. a medical apheresis unit). The apparatus includes primary and secondary vessels. Connected to the primary vessel is a first conduit which terminates at the treatment unit outlet, and a second conduit which terminates at the treatment unit inlet. Connected to the secondary vessel is a third conduit which terminates at the treatment unit inlet, and a fourth conduit which terminates at the treatment unit outlet. In use, a clamp is simultaneously secured to the first conduit and second conduit prior to filling the primary vessel with fluid (e.g. bone marrow). The clamp is then removed and placed on the first conduit and the third conduit simultaneously so that fluid flows from the primary vessel, into the treatment unit, and into the secondary vessel.

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 for removing leukocytes from a leukocyte-containing blood product, include subjecting a leukocyte-containing blood product to a first stage leukocyte-removing treatment to remove at least 60% of all leukocytes contained in the leukocyte-containing blood product, thereby obtaining a leukocyte-depleted blood product, and passing the leukocyte-depleted blood product through a microfilter element to perform a second stage leukocyte-removing treatment, the microfilter element having a non-woven or a woven fabric including fibers having an average diameter of from 0.3 to 1.6 .mu.m. A filter system for removing leukocytes from a leukocyte-containing blood product, to includes a first filter element for the first stage and a second filter element for the second stage, wherein the first filter element communicates with the second filter element and is positioned upstream of the second filter element with respect to a direction in which a leukocyte-containing blood product is to be flowed.

Abstract: A method for separating high density lipoproteins from blood serum or plasma. The method involves contacting the blood sample with an absorbant material comprising porous silica or silicate to adsorb the high density lipoprotein in preference to other lipoproteins in the blood sample. When combined with means for removing very low density lipoproteins and chylomicrons from the blood sample, the remaining low density lipoproteins can be measured directly.

Abstract: The invention concerns a process and a device for more efficiently obtaining a highly pure fraction of thrombocytes during density centrifugation of blood, which no longer has to be filtered before infusion into a patient for leukocytes contained therein, in order to prevent immunization of the recipient. The invention is based on a two-stage density separation, wherein in a first stage a separation is made between cells and thrombocyte-rich plasma, and the thrombocyte-rich plasma is not separated into a thrombocyte concentrate and thrombocyte-poor plasm until a second stage. During the first separation, the position of the phase boundary is changed cyclically in the first separation stage. Through alternating the phase boundary in the first stage, it becomes possible for the first time in the second stage to obtain highly pure thrombocyte concentrations with minimally low leukocyte contamination from the transferred thrombocyte-rich plasma without loss of efficiency.

Abstract: A method for the purification of Factor VIII from human plasma is described, wherein a solution comprising Factor VIII is purified by using ion exchange chromatographic columns. Factor VIII obtained by said method is also described.

Abstract: A method is provided for processing donated blood, particularly a platelet-containing solution such as platelet-containing plasma, involving separating blood into a red cell containing sediment layer and a supernatant layer, and passing the supernatant layer through a filter until the filter is blocked, thereby leaving platelets to be harvested. The preferred filter comprises a porous medium having a plurality of zones of progressively increasing density.

Abstract: Cytocentrifugation apparatus is improved by providing centrifuging devices with a plurality of liquid-receiving chambers arranged serially along and opening into an elongate conduit leading to and terminating within a filter-pad-holder so that a filter-pad-prewetting liquid can be passed along such conduit and into a liquid-flow opening of a filter pad held by such holder in advance of passage along said conduit and through such liquid-flow opening in the filter pad of a cell-carrying liquid sample during a centrifugation run of the apparatus. Retention of prewetting liquid in the filter pad around the sample liquid flow helps to prevent loss of cells to the filter pad. Various other structural modifications of the cytocentrifugation device and filter pads used therewith also help to prevent loss of cells to the filter pad.

Abstract: Platelet concentrate containing less then 10.sup.6 white blood cells and prepared from a unit of whole blood sample in a closed multiple blood bag system within less than about eight hours after the whole blood is removed from a human. The concentrate is contained in a platelet storage bag made from polyvinyl chloride plasticized with either trioctyltrimellitate or ethylene vinyl acetate.