US 5,736,033 A · Separator float for blood collection tubes with water swellable material

Abstract

A separator has a generally cylindrical body and a water swellable material fitted around at least a portion of the generally cylindrical body or on the surface of a passage through the body. Upon being exposed to water the water swellable material swells to form a seal in the passage or within the tube or other vessel containing the separator. The separator is preferably used in a blood collection tube and has a specific gravity between specific gravities of a light phase and a heavy phase of the blood. After the blood has been collected and centrifuged the separator moves to a position between the light phase and the heavy phase and the water swellable material is exposed to water in the blood causing the material to swell and create a seal. Thereafter, the serum or plasma as well as white blood cells, lymphocytes, monocytes and platelets can be removed from the blood collection tube.

Claims28

Dependent claims

A separator for use in a fluid collection tube which has at least one inner wall which defines a cavity for containing fluid, the separator comprised of:

a. a body sized and shaped to fit within the cavity with a fluid passage defined through the body or defined between the body and the at least one inner wall when the separator is placed in the fluid collection tube and comprised of at least one material which will not swell when in contact with water;
and
b. a water swellable material attached to the body, the water swellable material being sized and positioned so that when the separator is placed within the cavity and exposed to water containing fluid the water swellable material will swell so as to seal the fluid passage.

Dependencies are inferred from the claim text.

Separator float for blood collection tubes with water swellable material

Life of this patent

Separator float for blood collection tubes with water swellable material

Life of this patent

Abstract

Claims28