Centrifuge tube and method for collecting and dispensing mixed concentrated fluid samples

• US 6,401,552 B1
• Filed: 04/17/2000
• Issued: 06/11/2002
• Est. Priority Date: 04/17/2000
• Status: Expired due to Fees

• Current Assignee: Carlos D. Elkins
• Original Assignee: Carlos D. Elkins
• Inventors: Elkins, Carlos D.
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): SINES, BRIAN J
• Application Number:
  US09/551,221
• Time in Patent Office: 785 Days
• Field of Search: 436/46, 436/500, 422/100, 422/101, 422/102, 422/104, 422/71, 494/10, 494/16, 494/17, 435/102, 210/198.2, 210/359, 210/321.84, 210/650, 210/232, 738/63
• US Class Current: 73/863
• CPC Class Codes: B01L 3/5021 Test tubes specially adapted for centrifugation purposes centrifuges B04B5/04

Abstract

A centrifuge tube for collecting and dispensing a mixed concentrated fluid sample. The centrifuge tube has an elongated tube body with an open top end and a bottom end preferably having a dispensing spout. A divider insert is positioned inside the inner volume of the tube body to divide the inner volume into upper and lower chambers. The divider insert has a funnel shape with an inverted conical section and a funnel spout having a spout tip. The spout tip extends into the lower chamber while remaining above the bottom end. Upon filling the upper chamber with a fluid and subjecting it to centrifugal forces inside a centrifuge, a concentrated fluid sample is collected in the lower chamber with an air pocket captured between the spout tip and the divider insert. The concentrated fluid sample may then be agitated to mix the sedimented solids with the liquid of the concentrated fluid sample, and the now mixed concentrated fluid sample subsequently dispensed through the dispensing spout.

Claims

1. A centrifuge tube for collecting and dispensing a concentrated fluid sample, said centrifuge tube comprising:

an elongated tube body surrounding a tube volume, said elongated tube body having an open top end and a bottom end having a discharge opening;

discharge-opening occluding means adapted to be disengaged from a discharge-opening closing position to a discharge-opening open position; and

means for dividing said tube volume into an upper chamber adjacent said open top end, and a lower chamber adjacent said bottom end, said means for dividing having a funnel-shaped configuration with an inverted conical portion having an upper end sealingly positioned in said elongated tube body and said inverted conical portion having a lower conical surface having a passageway at a converging point thereof, said passageway communicating between said upper and lower chambers, said passageway having a lower terminus positioned in said lower chamber of said bottom end of said elongated tube body, thereby forming a volume between said lower conical surface and a horizontal plane intersecting said lower terminus.

2. The centrifuge tube as in claim 1,

wherein said means for dividing is a divider insert positioned within said tube volume, said divider insert having a contact surface adapted to snugly contact an inner surface of said elongated tube body and said lower terminus of said passageway located below said contact surface and above said bottom end.

3. The centrifuge tube as in claim 2,

wherein said elongated tube body is convergingly tapered toward said bottom end, whereby said divider insert is lodged in said elongated tube body near said bottom end.

4. The centrifuge tube as in claim 1,

wherein said bottom end of said elongated tube body has a discharge spout comprising said discharge opening at a tip thereof and said discharge-opening occluding means is a spout cap adapted to detachably mount on said discharge spout when in the discharge-opening closed position.

5. The centrifuge tube as in claim 1,

further comprising a top occluding means adapted to move between a top-open position and a top-closed position occluding said open top end.

6. The centrifuge tube as in claim 5,

wherein said top occluding means is a tube cap adapted to detachably mount on said open top end when in the top-closed position.

7. The centrifuge tube as in claim 6,

wherein said tube cap has means for controllably exerting pressure inside said tube volume whereby a fluid sample may be dispensed from said discharge opening.

8. The centrifuge tube as in claim 7,

wherein said means for controllably exerting pressure is a resiliently biasing surface formed in said tube cap.

9. The centrifuge tube as in claim 8,

wherein said resiliently biasing surface has a convex shape.

10. A method for collecting and dispensing concentrated fluid samples, said method comprising the steps of:

providing a centrifuge tube comprising,

an elongated tube body surrounding a tube volume, said elongated tube body having an open top end and a bottom end having a discharge spout with a discharge opening,

discharge-opening occluding means adapted to be disengaged from a discharge-opening closed position to a discharge-opening open position,

top occluding means adapted to move between a top-open position and a top-closed position occluding said open top end, and

means for dividing said tube volume into an upper chamber adjacent said open top end and a lower chamber adjacent said bottom end, said means for dividing having a contact surface for snugly contacting an inner surface of said elongated tube body, and a passageway communicating between said upper and lower chambers, said passageway having a lower terminus positioned in said lower chamber below said contact surface and above said bottom end of said elongated tube body;

in the discharge-opening closed position of said discharge opening and the top-open position of said open top end, filling said upper chamber with a fluid through said open top end;

occluding said open top end with said top occluding means;

subjecting said centrifuge tube to centrifugal forces in a centrifuge, whereby a concentrated fluid sample is collected in said lower chamber and an air pocket is captured between said lower terminus of said passageway and said means for dividing said tube volume;

agitating said lower chamber to mix any centrifuged material into any liquid in said lower chamber thereby forming a mixed concentrated fluid sample;

removing said discharge-opening occluding means from said discharge opening to the discharge-opening open position; and

dispensing said mixed concentrated fluid sample through said discharge opening.

11. The method as in claim 10,

wherein said top occluding means has means for controllably exerting pressure inside said tube volume;

wherein said step of dispensing said mixed concentrated fluid sample through said discharge opening includes the step of utilizing said means for controllably exerting pressure inside said tube volume.

12. The centrifuge tube as in claim 11,

wherein said means for controllably exerting pressure is a resiliently biasing surface formed on said top occluding means;

wherein said step of utilizing said means for controllably exerting pressure inside said tube includes the step of resiliently biasing said resiliently biasing surface.