# US 10,870,110 B2 · Specimen container and centrifugation method for separating serum or plasma from whole blood therewith > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,870,110 B2 - Document ID: US10870110B2 - Status: Granted - Kind: B2 - Application number: 16/061,309 - Filed: 2016-12-12 - Published: 2018-12-13 - Granted: 2020-12-22 - Earliest claimed: 2015-12-11 - Assignees: Babson Diagnostics, Inc. - Applicants: Babson Diagnostics, Inc. - Inventors: Eric Olson - Web page: https://patentgrep.com/patent/US10870110B2 ## CPC - B01L 3/50215: {using a float to separate phases} - B01D 21/26: Separation of sediment aided by centrifugal force {or centripetal force}(centrifuges B04B; cyclones B04C) - B01L 3/5021: {Test tubes specially adapted for centrifugation purposes} - G01N 21/07: Centrifugal type cuvettes (G01N21/09 takes precedence) - A61B 5/15003: {for venous or arterial blood} - A61B 5/154: {Devices} using pre-evacuated means - B01L 2300/042: Caps; Plugs - B01L 2300/044: pierceable, e.g. films, membranes - B01L 2300/047: Additional chamber, reservoir - B01L 2300/0832: cylindrical, tube shaped - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A device and method for separating serum or plasma from blood cells in a whole blood specimen. The present invention uses a cap with a reservoir, such that blood cells are packed into the cap when the specimen container is centrifuged. When the cap is removed, the blood cells are also removed, and the serum or plasma is left in the specimen tube where it can be readily extracted by a pipette which is able to reach all the way to the bottom of the specimen tube minimizing the dead volume. ## Claims ### Claim 1 A method of separating serum or plasma from a blood specimen comprising: with a specimen tube having an open end, a closed end, a lateral wall extending from the open end to the closed end, and a volume defined therebetween, disposing a blood specimen into the volume through the open end of the specimen tube; covering the open end of the specimen tube with a cap, the cap having an open end, a closed end, a lateral wall extending from the open end of the cap to the closed end of the cap, and a reservoir defined therebetween, with the cap secured to the specimen tube thereby enclosing the volume and reservoir to collectively form a specimen container therein, and with the blood specimen and a separator disposed within the specimen container, centrifuging the specimen container with the specimen container oriented with the closed end of the cap further away from an axis of centrifugation than the closed end of the specimen tube such that (1) blood cells of the blood specimen having a specific gravity greater than serum or plasma of the blood specimen migrate into the reservoir, and (2) the separator, having a specific gravity greater than the serum or plasma and less than the blood cells, migrates into the reservoir and between the blood cells and serum or plasma; and orienting the specimen container so that the closed end of the cap is oriented above the closed end of the specimen tube to enable gravity to move the serum or plasma towards the closed end of the specimen tube while the blood cells and separator remain in the reservoir of the cap, the cap being at least partially removable from the specimen tube to expose the open end of the specimen tube such that the serum or plasma can be withdrawn through the open end of the specimen tube. ### Claim 2 (depends on 1) The method of claim 1, further comprising: at least partially removing the cap from the specimen tube to expose the open end of the specimen tube and withdrawing the serum or plasma through the open end of the specimen tube. ### Claim 3 (depends on 1) The method of claim 1, wherein prior to the centrifuging, the cap is secured to the specimen tube such that the cap is spaced apart from the closed end of the specimen tube. ### Claim 4 (depends on 1) The method of claim 1, wherein prior to the centrifuging, the separator is disposed within the volume of the specimen tube. ### Claim 5 (depends on 1) The method of claim 1, wherein the volume of the specimen tube is about 0.1 mL to about 2.0 mL. ### Claim 6 (depends on 1) The method of claim 1, wherein the closed end of the specimen tube is round. ### Claim 7 (depends on 1) The method of claim 1, wherein the closed end of the specimen tube is conical. ### Claim 8 (depends on 1) The method of claim 1, wherein disposing the blood specimen into the volume through the open end of the specimen tube includes inserting the blood specimen into the volume of the specimen tube while the cap is still physically coupled to the specimen tube. ### Claim 9 (depends on 1) The method of claim 1, wherein the reservoir has a volume that is equal to or greater than the volume of the specimen tube. ### Claim 10 (depends on 1) The method of claim 1, wherein the specimen tube is tapered towards its closed end. ### Claim 11 (depends on 1) The method of claim 1, wherein the cap is disposed entirely outside the volume of the specimen tube when the cap is secured to the specimen tube. ### Claim 12 (depends on 1) The method of claim 1, wherein the lateral wall is continuous from the closed end of the specimen tube to the open end of the specimen tube. ### Claim 13 (depends on 1) The method of claim 1, wherein the covering the open end of the specimen tube includes circumferentially surrounding a portion of the specimen tube with a portion of the cap. ### Claim 14 (depends on 1) The method of claim 1, wherein the separator is a thixotropic gel. ### Claim 15 (depends on 1) The method of claim 1, wherein the separator is a mechanical separator. ### Claim 16 (depends on 1) The method of claim 1, wherein the separator is a filter-based separator. ### Claim 17 (depends on 1) The method of claim 1, wherein prior to centrifuging, the separator is in solid form, the centrifuging including liquefying the separator so that the separator can migrate within the specimen container and form a layer between the serum or plasma and the blood cells. ### Claim 18 (depends on 1) The method of claim 1, wherein the reservoir has a maximum cross-sectional area that is greater than a maximum cross-sectional area of the volume of the specimen tube. ### Claim 19 (depends on 1) The method of claim 1, wherein the cap is coupled to the specimen tube via a thread connection which secures the cap to an internal threading of the specimen tube. ### Claim 20 (depends on 1) The method of claim 1, wherein a portion of the reservoir extends into the volume of the specimen tube when the cap is secured to the specimen tube thereby enclosing the volume and reservoir to collectively from the specimen container therein. ### Claim 21 (depends on 1) The method of claim 1, wherein after centrifuging and before orienting the specimen container, the blood cells and the separator are disposed only in the reservoir, and a portion of the serum or plasma is disposed in the reservoir and a remaining portion of the serum or plasma is disposed in the volume of the specimen tube. ### Claim 22 (depends on 1) The method of claim 1, wherein after centrifuging and before orienting the specimen container, the blood cells, the separator, and the serum or plasma are disposed only in the reservoir. ### Claim 23 A method of separating blood cells from a blood specimen with a specimen container, the specimen container including a specimen tube defining an inner volume, and a cap defining a reservoir, the method comprising: disposing the blood specimen into the inner volume through an open end of the specimen tube; securing the cap to the specimen tube, thereby enclosing the inner volume and the reservoir; with a separator disposed within at least one of the inner volume or the reservoir, disposing the specimen container in a centrifuge, the centrifuge having an axis of centrifugation; centrifuging the specimen container with the cap further away from the axis of centrifugation than a closed end of the specimen tube such that the blood cells of the blood specimen and the separator migrate into the reservoir and remain in the reservoir after the centrifuging; and orienting the specimen container with the cap above the closed end of the specimen tube, the cap being at least partially removable from the specimen tube to expose the open end of the specimen tube such that the serum or plasma can be withdrawn through the open end of the specimen tube. ### Claim 24 (depends on 23) The method of claim 23, wherein the volume of the specimen tube is about 0.1 mL to about 2.0 mL, and the closed end of the specimen tube is round. ### Claim 25 (depends on 23) The method of claim 23, wherein prior to the centrifuging, the cap is secured to the specimen tube such that the cap is spaced apart from the closed end of the specimen tube. ### Claim 26 (depends on 23) The method of claim 23, wherein the separator includes at least one of a thixotropic gel, a mechanical separator, or a filter-based separator. ### Claim 27 A method of separating blood cells from a blood specimen with a specimen container, the specimen container including a specimen tube defining an inner volume, and a cap defining a reservoir, the method comprising: disposing the blood specimen into the inner volume through an open end of the specimen tube; securing the cap to the specimen tube, thereby enclosing the inner volume and the reservoir; disposing the specimen container in a centrifuge, the centrifuge having an axis of centrifugation; centrifuging the specimen container with the cap further away from the axis of centrifugation than a closed end of the specimen tube such that the blood cells of the blood specimen migrate into the reservoir and remain in the reservoir after the centrifuging; and orienting the specimen container with the cap above the closed end of the specimen tube, the cap being at least partially removable from the specimen tube to expose the open end of the specimen tube such that the serum or plasma can be withdrawn through the open end of the specimen tube, the reservoir in the cap having a volume (1) defined as the maximum amount of liquid that can be contained in the cap without contacting the specimen tube and (2) equal to or greater than a volume of the blood cells and other solids separated from the blood specimen. ### Claim 28 (depends on 27) The method of claim 27, wherein the centrifuging occurs without a separator disposed in the inner volume and without a separator disposed in the reservoir, and such that the centrifuging packs the blood cells in the reservoir such that the blood cells remain in the cap after the centrifuging and when the cap is at least partially removed from the specimen tube to expose the open end of the specimen tube. ### Claim 29 (depends on 27) The method of claim 27, wherein the reservoir has a maximum cross-sectional area that is greater than a maximum cross-sectional area of the volume of the specimen tube. ### Claim 30 (depends on 27) The method of claim 27, wherein a portion of the cap circumferentially surrounds a portion of the specimen tube when the cap is secured to the specimen tube.