Simultaneous cuvette filling with means to isolate cuvettes

• US 5,409,665 A
• Filed: 09/01/1993
• Issued: 04/25/1995
• Est. Priority Date: 09/01/1993
• Status: Expired due to Term

• Current Assignee: Abaxis Incorporated (Zoetis Incorporated)
• Original Assignee: Abaxis Incorporated (Zoetis Incorporated)
• Inventors: Burd, Tammy L.
• Primary Examiner(s): Jones, W. Gary
• Assistant Examiner(s): EDWARDS, LAURA ESTELLE
• Application Number:
  US08/115,163
• Time in Patent Office: 601 Days
• Field of Search: 422/72, 422/101, 422/64, 494/17, 436/45, 436/177, 210/787, 210/789, 210/360.1
• US Class Current: 422/64
• CPC Class Codes: G01N 21/07 Centrifugal type cuvettes G01N21/09 takes precedence
• CPC Class Codes: G01N 33/491 by separating the blood components G01N15/05 takes precedence
• CPC Class Codes: Y10T 436/111666 Utilizing a centrifuge or compartmented rotor
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]

Abstract

The present invention provides centrifugal rotors for delivering a liquid, typically a biological sample such as diluted plasma, to a plurality of cuvettes in the rotor. The cuvettes are positioned radially inward of an annulate manifold and are connected to the manifold through a plurality of inlet channels. The liquid is introduced in one end of the manifold and, as the rotor spins, the liquid fills the manifold from the radially outward edge inward. After, the manifold fills, the liquid flows radially inward through the inlet channels into the chambers. The design allows the simultaneous filling of the cuvettes. The inlet channels may also be sized such that as liquid enters the cuvettes, gas escapes through the inlet channel.

Claims

1. A centrifugal rotor comprising a rotor body having an axis of rotation and a manifold circumferentially disposed in the rotor body, the manifold having a first end and a second end, a means disposed at the first end for introducing a liquid into the manifold, a plurality of chambers positioned radially inward of the manifold, and a plurality of inlet channels connecting the chambers to the manifold, whereby spinning the rotor body causes the liquid introduced into the manifold to flow through the inlet channels into the chambers.

2. The rotor of claim 1, wherein each inlet channel has a generally U-shaped portion, whereby spinning the rotor causes the liquid in the manifold to flow radially inward through the inlet channels to the U-shaped portion and then radially outward into the chambers.

3. The rotor of claim 2, wherein the generally U-shaped portion of each inlet channel is positioned at the same radial distance from the axis of rotation, thereby allowing parallel filling of the chambers.

4. The rotor of claim 1, wherein the means for introducing a liquid into the manifold comprises a sample reservoir positioned radially inward of the manifold and a feeding channel connecting the sample reservoir to the first end of the manifold.

5. The rotor of claim 4, wherein the cross-sectional area of the feeding channel is less than the cross-sectional area of the manifold and inlet channels, thereby causing resistance to flow of liquid in the feeding channel to be greater than resistance to flow of liquid in the manifold and the inlet channels.

6. The rotor of claim 4, wherein the feeding channel is straight.

7. The rotor of claim 1, further comprising an excess liquid dump positioned radially outward of the manifold and an excess liquid channel connecting the excess liquid dump to the manifold, the excess liquid channel being connected to the second end of the manifold.

8. The rotor of claim 7, wherein the excess liquid channel is a siphon.

9. The rotor of claim 8, wherein each inlet channel has a U-shaped portion and the siphon has an elbow positioned radially inward of the U-shaped portions of the inlet channels.

10. The rotor of claim 8, wherein the cross-sectional area of the siphon is less than the cross-sectional area of the feeding channel thereby causing resistance to flow of liquid in the siphon to be greater than resistance to flow of liquid into the manifold.

11. The rotor of claim 1, further comprising a venting manifold positioned radially inward of the chambers and a plurality of venting channels connecting each chamber to the venting manifold.

12. The rotor of claim 11, wherein the means for introducing a liquid into the manifold comprises a sample reservoir positioned radially inward of the manifold;

14. The rotor of claim 1, wherein the manifold has an axis of rotation positioned away from the axis of rotation of the rotor body.

15. The rotor of claim 1, wherein the chambers are cuvettes.

16. The rotor of claim 14, wherein each cuvette comprises reagents necessary for analysis of blood.

17. The rotor of claim 1, wherein the manifold is annulate.

13. the venting manifold is positioned radially outward of the sample reservoir and a pocket for holding excess liquid is positioned radially inward of each chamber.