Abstract: A rotary vessel for a filter assembly is rotatably mountable in a housing of the filter assembly and has a body having an open end, a cover receivable on the body to close the open end, and a releasable locking device that is manually operable to selectively lock and unlock the cover relative to the body.

Abstract: The present invention relates to a platelet rich plasma (PRP) extracting device and extracting method using the same, and more particularly, to a platelet rich plasma (PRP) extracting device capable of quickly and effectively extracting the highly concentrated PRP from centrifuged blood by a simple manipulation.

Abstract: A rotary vessel for a filter assembly is rotatably mountable in a housing of the filter assembly and has a body having an open end, a cover receivable on the body to close the open end, and a releasable locking device that is manually operable to selectively lock and unlock the cover relative to the body.

Abstract: Provided is a reagent cartridge configured to be set in a genetic testing device and the reagent cartridge includes a plurality of reagent containers in which a reagent is filled, and a holder formed with a plurality of opening parts in which the reagent containers are loaded and configured to hold the reagent containers loaded in the opening parts, in which the holder holds the reagent containers with an allowance in a vertical direction in a state in which the reagent cartridge is set in the genetic testing device.

Abstract: A washed platelet having a sufficiently low blood plasma content rate is more securely and efficiently obtained. A tertiary separator (42) includes a main body (58) which has a third chamber (52) and is formed as an accommodating portion (54a) accommodating a centrifuged platelet (104), an inlet (77c) which allows a platelet containing component (100) and a platelet added solution (102) to flow in, and an outlet (78a) which allows blood plasma, the platelet added solution (102), and the platelet (104) to flow out. A bottom portion (first bottom portion (60)) of at least a portion forming the accommodating portion (54a) in a wall portion included in the main body (58) is formed of a soft material.

Abstract: The invention relates to a rotor (10) of a dual centrifuge wherein the rotor has a rotor head (12) and an additional rotational mechanism for at least one rotational unit (22) which is provided in the rotor head (12) and comprises a bearing unit (70) and a rotational head (24) that is connected to the bearing unit (70) which is rotatably mounted and can be driven relative to the rotor head (12) by an additional rotational mechanism, an opening (16) for the rotational unit (22) being provided in which the rotational unit is accommodated and by means of which the bearing (70) is arranged such that it is fixed relative to the rotor head (12).

Abstract: Provided is a centrifuge. In a centrifuge having a rotor with a rotor body that holds a sample and that is rapidly rotated, an inclined surface that extends upward as it extends radially outward is formed on an upper-side outer peripheral portion of the rotor, in a region that is at a radially outward side and at an upper side of the outer edge of an opening. The inclined surface is a continuous ring-like inclined surface that has the same cross-sectional shape in the circumferential direction and is formed into a straight-line shape or a curved-line shape in cross-section along a rotation central axis. Although winds occur during high-speed rotation of the rotor, the winds are rectified by the inclined surface, and a component force for pressing the rotor body in a downward direction acts thereon.

Abstract: A centrifuge rotor assembly includes a chamber assembly, a bearing support, and a counterweight that is substantially diametrically opposed to the bearing support with respect to the chamber assembly. The chamber assembly receives a processing chamber of a fluid circuit, while the bearing support receives a portion of an umbilicus that is fluidly connected to the processing chamber. The bearing support and counterweight are rotated about a central axis of the chamber assembly by an electric drive of the centrifuge rotor assembly, with the bearing support and counterweight remaining substantially diametrically opposed to each other with respect to the chamber assembly while being rotated about the central axis. The electric drive may rotate the bearing support and counterweight at a plurality of different speeds, with the counterweight automatically moving with respect to the bearing support between radially innermost and radially outermost positions to balance the centrifuge rotor assembly.

Abstract: An adapter for a jar for use with a planetary mixer, the adapter securing a dispensing container having a body and a removable cap, the adapter having a central aperture through which a longitudinal axis of the jar passes when the adapter is inside the jar. When the dispensing container is secured to the adapter and the adapter is inside the jar: (i) the adapter maintains the container spaced from an inner wall and from a bottom of the jar; (ii) a gap is provided between a top of the jar and the container; (iii) a point on the cap of the container extends further from the bottom of the jar than does a point on the body of the container; (iv) the body of the container crosses the longitudinal axis of the jar; and (v) the container extends over more than half the diameter of the jar.

Abstract: The invention relates to a rotational unit (10) for a rotor of a dual centrifuge, said rotational unit having a bearing (14) and a rotational head (24) which is connected to the bearing (14), is mounted therein such that it can rotate about an axis of rotation and can be driven relative to the rotor by an additional rotational mechanism of the centrifuge, the rotational head (24) being detachably connected to the receiving unit (40, 80) for conjoint rotation, which receiving unit comprises a sample container receptacle (60, 70, 100, 110) for at least one sample container.

Abstract: An apparatus having a plate mountable on an oscillating multi-function tool and having a plurality of sample apertures sized to receive sample vials. The sample apertures may be lined with resilient grommets or have a chamfered edge. The apparatus may further have a weighted base and housing with vibrating isolation means for holding the tool during operation. The apparatus may further have a timer to allow for timed operation. The method including providing a plate mounted on the arbor of an oscillating multi-function tool, inserting a sample vial in a sample aperture and turning on the tool. The method may further include operating the tool for a fixed time and providing a housing and base to hold the tool during operation.

Abstract: A support structure for a rotation driving system having a ball balancer includes: a motor having a rotational shaft coupled to a rotational shaft of a rotor; the ball balancer provided on the rotor to reduce oscillating motion of the rotor; and a support part for coupling the motor to a housing, wherein the motor is coupled to the housing via an elastic member on a line in one direction (x-axis) perpendicular to an axial direction (z-axis) of the rotational shaft of the motor, and the motor is allowed to swing about the x-axis due to elastic deformation of the elastic member.

Abstract: A fixed angle centrifuge rotor includes a rotor body having a circumferential sidewall and a plurality of circumferentially spaced tubular cavities. Each tubular cavity has an open end and a closed end, and is configured to receive a sample container therein. The rotor further includes a pressure plate operatively coupled to the rotor body so that the pressure plate, in combination with the plurality of tubular cavities and the circumferential sidewall of the rotor body, define a hollow chamber within the rotor. The rotor further includes a plurality of elongated torque transfer members supported by the rotor body and an annular containment groove.

Abstract: A fixed angle centrifuge rotor includes a rotor body having a circumferential sidewall and a plurality of circumferentially spaced tubular cavities. Each tubular cavity has an open end and a closed end, and is configured to receive a sample container therein. The rotor further includes a pressure plate operatively coupled to the rotor body so that the pressure plate, in combination with the plurality of tubular cavities and the circumferential sidewall of the rotor body, define a hollow chamber within the rotor. The rotor further includes a plurality of elongated torque transfer members supported by the rotor body and an annular containment groove.

Abstract: A fixed angle centrifuge rotor includes a rotor body having a circumferential sidewall and a plurality of circumferentially spaced tubular cavities. An annular containment groove is disposed above and circumferentially surrounds the tubular cavities. Each tubular cavity has an open end and a closed end, and is configured to receive a sample container therein. The rotor further includes a pressure plate operatively coupled to the rotor body so that the pressure plate, in combination with the plurality of tubular cavities and the circumferential sidewall of the rotor body, define a hollow chamber within the rotor. The pressure plate includes circumferentially spaced upstanding tabs that are received in respective pockets located between adjacent tubular cavities. The rotor further includes a plurality of elongated torque transfer members supported by the rotor body.

Abstract: An example includes an apparatus for separating cells from a fluid sample, including a plenum, defining: a centrally located top inlet, and respective side outlets disposed below the inlet and to the side of the inlet; and a bottom outlet disposed below the top inlet, to the side of the two or more outlets, wherein the plenum is configured to receive a fluid and cells suspension through the inlet, and direct it to the bottom outlet, against respective side-walls extending between the bottom outlet and the two or more side outlets, and wherein the distance between each of the two or more side outlets and the bottom outlet is selected to encourage cells to exit through the bottom outlet under a force. Lateral/vertical distance between the inlet and side outlets can provide lateral fluid travel, thereby allowing time for gravity to bias cells toward an outlet.

Abstract: An automated process for converting samples includes: receiving tube strips having a number of sample tubes and samples therein, transferring multiple tube strips to a tube strip holder, dispensing sample conversion buffer into each tube, shaking the tube strip holder a first time, centrifuging the tube strip holder, removing a liquid supernatant from each tube, simultaneously inspecting the contents of each tube, dispensing a specimen transport medium and a denaturation reagent into each tube, shaking the tube strip holder a second time, heating the tube strip holder for a first length of time, shaking the tube strip holder a third time, heating the tube strip holder for a second length of time, shaking the tube strip holder a fourth time, and transferring at least a portion of each sample to a respective well on an output plate.

Abstract: A rotor includes a plurality of holding cavities for holding specimen containers, respectively. A transverse cross sectional shape of the holding cavity is a substantially triangular shape having one vertex on an inner circumference side of the rotor. Two vertices of the substantially triangular shape are arranged on an outer circumference side of the rotor so as to have equidistance from a rotary shaft of the rotor. Spacing between sides of the substantially triangular shape in a circumferential direction of the rotor gradually increase over 60% or more a radial length of the holding cavity from an innermost circumferential position to the outer circumference side of the rotor when viewed in its transverse plane.

Abstract: A centrifuge to which sample tubes can be introduced while the centrifuge is in motion. The centrifuge comprises a carousel having an upper portion and a lower portion. The upper portion of the carousel has a plurality of positions for sample tubes for a centrifugation operation, a plurality of drive mechanisms attached to the upper portion of the carousel, a movable element mounted upon each drive mechanism, the movable element capable of traversing the length of the drive mechanism when the drive mechanism is actuated, a sample tube-holding assembly comprising a sample tube holder and a bearing attached to each movable element, and at least one balancing element capable of contributing to a force vector that cancels an imbalance vector generated by rotation of the centrifuge.

Abstract: The invention relates to an adapter for a centrifuge vessel having a shell-shaped base body formed as one piece and delimiting a cavity for the purpose of accommodating the centrifuge vessel and comprising a base region and an adjacent side-wall region of which the top edge defines the opening edge of the cavity, at least one expansion joint being present in the side-wall region, which expansion joint when subjected to a force allows for moving the side-wall region from a starting position to an expanded position such that the length of the opening edge is greater in the expanded position than in the starting position. The adapter is made of a plastics material such that when the force is removed from the side-wall region the base body automatically returns to the starting position.

Abstract: A centrifuge for high-speed centrifuging, includes: a shaft, mounted for continuous rotation about its axis, the shaft having a working section having a loading end and an unloading end; an acceleration member mounted adjacent to the loading end for rotation with respect to the shaft and; a deceleration member mounted adjacent to the unloading end for rotation with respect to the shaft; auxiliary drive arrangement for accelerating the acceleration member and the deceleration member to the shaft speed; carriages for supporting specimens for centrifugation. The carriages are slideably mounted for traversing from the acceleration member to the working section and from the working section to the deceleration member. A carriage may be accelerated on the acceleration member and then transferred to the working section for a period sufficient to perform centrifuging and then transferred from the working section to the deceleration member.

Abstract: A gripper unit for handling a vessel for receiving biological material is proposed, inter alia. The vessel has a lid which can assume an open position and a closed position. The gripper unit comprises a gripper for gripping and releasing the vessel, and a lid holder, for holding a lid in a defined position in relation to the vessel. The defined position is an open position of the lid.

Abstract: A revolver component for a reagent vessel has at least one first chamber that is configured to be filled at least partly with at least one liquid. The first chamber is formed or fitted such that a first chamber filling volume that is configured to be filled with the at least one liquid is delimited by an expansion-variable boundary. The expansion-variable boundary has a spatial expansion that can be reversibly adjusted such that the filling volume is configured to be varied. Reagent vessel insert parts and reagent vessels are also disclosed. Methods for centrifuging a material and for pressure treating a material are also disclosed.

Abstract: A hand-cranked centrifuge is adapted for use in isolating autologous fat in injectible from. A number of syringes are hingeably coupled to a flywheel of the centrifuge. As the centrifuge turns, the syringe(s), which are supported at one end, move into a horizontal orientation and are centrifuged until the fats get separated from other liquids present in the syringes. A number of syringes, syringe holders and related devices are disclosed to accommodate centrifugation.

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: The invention refers to a centrifuge for separating whole blood into its blood components and a method for extracting a highly enriched thrombocyte concentrate out of whole blood. For this purpose, the centrifuge comprises a closed loop and/or open-loop control unit as well as a drive unit coupled to the closed loop and/or open-loop control unit, a rotor (12) having at least two container receptacles (14a, 14b; 16a, 16) for removably holding containers (18, 20, 22, 24) being in fluid communication with each other, at least one sensor arranged between the container receptacles (14a, 14b; 16a, 16b) and coupled with the closed loop and/or open-loop control unit for detecting a separation layer. Herein, a motor/gear unit (30a, 30b, 32a, 32b) coupled to the closed loop and/or open-loop control unit is associated with each of the container receptacles (14a, 14b; 16a, 16b).

Abstract: The invention relates to a sample carrier centrifuge for a sample carrier (24) that has at least one sample channel (26) extending along an essentially central sample channel longitudinal axis (P), having a sample carrier receptacle (14), which can be rotated around a rotation axis (R) and has a holding section (38) into which the sample carrier (24) can be inserted in a loading procedure when the sample carrier receptacle (14) is not rotating, in which section the sample carrier (24) is held in the loaded state of the sample carrier receptacle (14), and from which section the sample carrier (24) can be removed in an unloading procedure, which is characterized in that a platform (22) of the sample carrier centrifuge (10), which is embodied for supporting the sample carrier centrifuge (10) in accordance with its designated use, is oriented parallel to the rotation axis (R).

Abstract: A gripper unit for handling a vessel for receiving biological material is proposed, inter alia. The vessel has a lid which can assume an open position and a closed position. The gripper unit comprises a gripper for gripping and releasing the vessel, and a lid holder, for holding a lid in a defined position in relation to the vessel. The defined position is an open position of the lid.

Abstract: Systems and methods are provided for processing blood or a fluid containing blood plasma and platelets. The blood or fluid is continuously added into a fluid separation chamber, which is used to isolate platelet-rich plasma therein. At least a portion of the platelet-rich plasma is automatically transferred from the fluid separation chamber into an injection device, with the fluid separation chamber and the injection device comprising components of a disposable flow circuit, which may be a closed system. One or more injection devices may be connected to a collection container or a pump device of the disposable flow circuit.

Abstract: A locking system for axially securing a rotor onto a rotatably mounted shaft. The arrangement includes a plurality of locking levers which are each pivotably mounted about axes extending perpendicularly to the shaft between a locking position and an unlocking position in planes containing the axes. The locking levers can each be automatically transferred between an unlocking position and a locking position depending on rotational speed. The locking levers are mounted on the rotor and an annular groove is provided on the shaft and engages with the locking levers in the locking position, wherein the locking levers are prestressed in the unlocking position. Advantageously, the rotor can be both installed and removed without tools by merely placing the rotor onto or removing the rotor from the shaft, in each case depending on rotational speed.

Abstract: Systems and methods are provided for sample processing. A device may be provided, capable of receiving the sample, and performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing multiple assays. The device may comprise one or more modules that may be capable of performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing the steps using a small volume of sample.

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 centrifugal separating assembly for separating a fluid biological product into discrete components by centrifugation is disclosed. The assembly includes a first container defining a first cavity adapted to receive a human biological product, the first container having a circular upper wall, a cylindrical sidewall, and a concave shaped bottom wall. The assembly further includes a second container defining a second cavity adapted to receive discrete components, the second container having a convex shaped upper wall, a second cylindrical wall, and a circular bottom wall; and a tubular conduit providing fluid communication between the first cavity and the second cavity.

Abstract: The present invention relates to improved methods for processing fluids and to a fluid processing device (1) for use in a centrifuge comprising: (a) a first holder (14) form-fit to the shape of a first tube (18) for holding said first tube (18) whereby said first tube (18) has a first cross section (A1); and (b) a second holder (22) form-fit to the shape of a second tube (26) for holding said second tube (26) whereby said second tube (26) has a second cross section (A2) that is different from said first cross section (A1). With the fluid processing devices and the methods according to the invention, it is possible to simplify the centrifugal processing steps for a given fluid processing sequence and to automate them.

Abstract: The present invention relates to a centrifuge insert for sample holders and to a carrier for a centrifuge insert for sample holders. The centrifuge insert according to the invention has substantial advantages over known centrifuge inserts. These advantages are not limited to the fact that the carrier is attachable and detachable in a particularly easy and comfortable manner. It is also feasible to use different carriers for different sample holders. Furthermore, the centrifuge insert according to the invention is configured particularly light and compact so that the loading of the rotor is significantly lower for identical centrifugation powers or so that significantly higher RCA values can be used.

Abstract: Methods and devices for molecular analysis are disclosed, based on centrifugation. A centrifuge device comprises strips of centrifuge tubes and elements to create a magnetic field. The magnetic shear forces applied to beads inside a solution with biological molecules permit the performance of different analytic techniques, such as lysis and sample preparation for PCR.

Abstract: The invention relates to a centrifuge with a drive head which can be connected with a drive, a rotor which can detachably be mounted on the drive head, at least one connection element with which the drive head can be connected in a torsion-proof manner with the rotor, and at least one coupling element which is attached to the drive head and is able to exert an axial force on the rotor in such a way that the rotor can be fixed axially, with the axial force increasing with the rising rotational speed of the drive head, with the coupling element on the rotor transmitting the axial force by means of a ramp surface which is inclined at an angle (?) relative to the horizontal line in a range of more than 0° to 15°. Secure locking of the rotor during standstill and high speeds can thus be achieved.

Abstract: An automated centrifuge apparatus for conducting a cell preparation procedure is provided. A rotor assembly supports centrifuge tubes, which are installable at respective tube positions. The tube positions are indexable to an index location. A sensing module monitors the index location during a set of status checks, which relate to the centrifuge tubes. Logic signals generated by the sensing module are used to automatically determine whether the status checks are satisfied.

Abstract: A chemical analyzer, a method for sample-based analysis, a device for handling cuvette assemblies including a rotatable incubator with at least one curved opening for receiving a new cuvette assembly, an analyzer arranged around the incubator for analyzing contents of the new cuvette assembly, and a loading device adapted to carry the new cuvette assembly while initially being aligned in a straight manner before being loaded. The loading device includes a feed funnel having a first end for receiving the new cuvette assembly initially aligned in the straight manner into the feed funnel, and a second end for feeding the new cuvette assembly into the at least one curved opening, the second end having a curvature which corresponds to the curvature of the curved opening, the second end for bending the initially straight new cuvette assembly and fitting the new cuvette assembly into the at least one curved opening.

Abstract: Illustrative embodiments of automated sample workcells and methods of operation are disclosed.

Abstract: The present invention relates to a method and device for separating and transferring container (1) contents by dynamical use of centrifuge force, transferring a specific volume of liquid (A) from a recipient (1) to another (2) without contact with any external element other than the initial container (1) itself. Therefore, the present invention is useful for transferring for example part of a blood sample (A) from a tube (1) without touching the blood sample, also dispensing with a disposable needle as is currently usual. The invention is also advantageous as it allows keeping in the original container (1) a predetermined portion of the sample (B). By rotating the container, with a sufficiently high speed, over an axis (x) located at the boundary of the parts (A, B), the sample is split at a predetermined position. A preferred embodiment comprises the container at an angle (V) to the rotation axis (x).

Abstract: A separation system for separating a multiple component material into at least two fractions. The separation system includes a separation device having a first end, a second end opposite to the first end, and a sidewall that extends between the first end and the second end to define a separation chamber having an interior volume. The system also includes a valve moveable between an open position and a closed position, the valve is mounted at a fixed location within the separation chamber at a position that is closer to the second end than to the first end and is spaced apart from the second end, the valve is operable to isolate a first fraction of the multiple component material having a first density on a first side of the valve from a second fraction having a second density on a second side of the valve that is opposite to the first side.

Abstract: A centrifuge is provided. The centrifuge includes a power source, the power source configured to generate electrical power from a renewable power source. At least one battery electrically coupled to the power source. A motor is electrically coupled to the at least one battery. A rotor is coupled to the motor. The rotor has a generally cylindrical body and a pair of opposing openings opposite the motor, and a pair of holders each disposed in one of the pair of opposing openings, each of the holders having an opening on one end sized to receive a capillary tube.

Abstract: Centrifuges have been designed in the past for centrifuging multi-welled containers, but they are limited in centripetal acceleration or have a large footprint. The invention provides a centrifuge with a high centripetal acceleration and imbalance tolerance while maintaining a small footprint and being able to integrate with laboratory automation equipment. Methods and apparatuses for centrifugation include a rotor assembly positioned within a shield assembly suspended in a centrifuge. The rotor assembly is operably connected to the motor for rotating payloads (e.g., multi-welled containers) around an axis. The shield assembly is positioned such that the center of mass is aligned with the axis of rotation of the rotor assembly and the plane containing the rotational imbalance force vector. This alignment allows rotation of the container with an acceleration of at least 2000 g (or at least 3000 g, 4000 g, 5000 g, etc.).

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: A centrifugal processing bag, system and method for separating the components of a mixed material is presented. The processing bag includes a hub and a first port for receiving the mixed material, where the first port includes an outlet positioned within the processing bag at a perimeter of the bag. The processing bag also including a second port having a second port inlet spaced proximate the hub and away from a central axis of the hub. The second port directs a separated material collected from the second port inlet out of the processing bag.

Abstract: A microfluidic flow cell for removably interfacing with a removable-member for performing a reaction therebetween. The microfluidic flow cell device comprises at least one reaction portion defining with the removable-member a reaction chamber when in an interfaced position thereof. The microfluidic flow cell comprises at least one fluid-receiving portion for receiving a fluid therein and being in fluid communication with the reaction chamber. When the microfluidic flow cell and the removable-member are in the interfaced position, the cell is adapted to allow for the fluid in the fluid-receiving portion to flow to the reaction chamber. Devices, systems and methods comprising this microfluidic flow cell are also disclosed.

Abstract: A centrifuge rotor cover has a lid, a circular plate attached to the lid with click holes formed in a circle, a knob and knob shaft, a plate spring attached to a surface of the knob facing the circular plate and an elastic body pushing the lid against the rotor depending on the distance between the knob and the lid. If this distance is equal to or less than a predetermined value, the plate spring is caught repeatably in the click holes as the knob is turned to cause sounds and vibrations that indicate the knob is not tightened securely.

Abstract: Systems and methods are provided for sample processing. A device may be provided, capable of receiving the sample, and performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing multiple assays. The device may comprise one or more modules that may be capable of performing one or more of a sample preparation, sample assay, and detection step. The device may be capable of performing the steps using a small volume of sample.

Abstract: A blood specimen processor by means of which blood specimens are collected into a collection tube containing an anticoagulant and a molded buoy of predetermined density between 1.045 and 1.084 with an embedded water swellable o-ring that expands to form a robust seal in a leucocyte density gradient between the buoy's outer surface and tube's inner surface. The buoy is made of a first resin and a second resin, the first resin having a lower density than the second resin, the first resin and the second resin being present in such amounts and relative proportions so that the body has an overall density between 1.045 and 1.084 and preferably, a center of gravity below a geometric center of the body. When the blood specimen contained in the processor is centrifuged, the buoy is thrust through the separating blood and the developing interface of erythrocytes, leucocytes, and plasma.