Specimen container and centrifugation method for separating serum or plasma from whole blood therewith
AssigneeBabson Diagnostics, Inc.
InventorEric Olson
Life of this patent
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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.
Claims30
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removable from the specimen tube to expose the open end of the specimen tube such that the serum or plasma can be withdrawn through the open end of the specimen tube.
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.
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.
Dependencies are inferred from the claim text.