Automated patient sample analysis instrument having tubes and reaction wells washing apparatus

• US 5,650,122 A
• Filed: 06/06/1995
• Issued: 07/22/1997
• Est. Priority Date: 10/31/1986
• Status: Expired due to Fees

• Current Assignee: Pasteur Sanofi Diagnostics
• Original Assignee: Pasteur Sanofi Diagnostics
• Inventors: Harris, Paul C., Genstler, Curtis C.
• Primary Examiner(s): Le, Long V.
• Application Number:
  US08/470,637
• Time in Patent Office: 777 Days
• Field of Search: 422/63, 422/64, 422/65, 422/67, 422/68.1, 422/81, 422/100, 436/43, 436/47, 436/49, 436/50, 436/55, 436/174, 436/180, 436/54, 134/88, 73/864.61, 73/864.11, 73/864.12, 73/864.22, 15/302, 15/320, 15/321
• US Class Current: 422/81
• CPC Class Codes: G01N 2035/00752 bar codes
• CPC Class Codes: G01N 2035/1025 Fluid level sensing
• CPC Class Codes: G01N 35/028 having reaction cells in the form of microtitration plates
• CPC Class Codes: G01N 35/1083 with one horizontal degree of freedom
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/113332 with conveyance of sample along a test line in a container or rack
• CPC Class Codes: Y10T 436/114998 with treatment or replacement of aspirator element [e.g., cleaning, etc.]
• CPC Class Codes: Y10T 436/119163 with aspirator of claimed structure
• CPC Class Codes: Y10T 436/2575 Volumetric liquid transfer

Abstract

An automated sample analysis instrument positively identifies and maintains the identity of a plurality of patient samples contained in individual sample containers. The invention prevents sample misidentification, especially when patient sample must be transferred from one sample container to reaction wells in Microtiter® plates. Rows of reaction wells in Microtiter® plates are processed in parallel so the difference in reaction time between any two wells on a plate is four minutes or less. Reaction wells are washed with high-pressure jets of wash solution and are aspirated so as to advantageously utilize fluid meniscus on top of fluid contained in the wells. The apparatus can be adjusted to perform a variety of different ELISA-type tests.

Claims

1. An apparatus for removing sample fluid from an open top reaction well, said apparatus comprising:

an elongated aspiration tube movable between a retracted position and an extended position and having a fluid inlet positionable above the reaction well top when the aspiration tube is in a retracted position and positionable adjacent to the reaction well bottom when the aspiration tube is in the extended position, and vacuum means for establishing a regulated partial vacuum in the aspiration tube;

means for controllably moving the aspiration tube between the retracted and extended positions, in coordination with vacuum means, so that a rate at which the aspiration tube is lowered into the well is approximately equal to a rate at which fluid level is falling in the well, allowing the fluid inlet of the aspiration tube to remain in contact with the fluid in the reaction well as the fluid is being removed, whereby a fluid meniscus formed by fluid surface tension leaves the wall of the reaction well substantially dry; and

a wash tube having a fluid outlet, said wash tube positioned to direct a flow of wash solution to impinge on said aspiration tube and spray the wash solution into said reaction well positioned therebelow, and means for charging the wash tube with said flow of wash solution to wash the reaction well and the aspiration tube.

2. The apparatus of claim 1, wherein the interior diameter of the aspiration tube is approximately 0.033 inch.

3. The apparatus of claim 1, wherein the reaction well is a microwell.

4. The apparatus of claim 1, wherein the vacuum means comprises a vacuum pump.

5. The apparatus of claim 1, wherein the aspiration tube is connected to an aspiration line, which line is further connected to said vacuum means and controlled by a solenoid-operated liquid pump.

6. The apparatus of claim 1, wherein the aspiration tube is positioned substantially vertically and wherein the wash tube is positioned with respect to the aspiration tube at an angle of approximately 15°

.

7. The apparatus of claim 1, wherein the wash tube has an interior diameter of approximately 0.027 inch and the means for charging the wash tube is adapted to deliver fluid through the wash tube at a rate of between about 1 microliter per 100 seconds and about 1 microliter per 200 seconds.

8. The apparatus of claim 1, wherein the wash tube charging means includes a solenoid-operated liquid pump.

9. An apparatus for removing sample fluid from a reaction well, said apparatus comprising:

an elongated aspiration tube having a fluid inlet, the aspiration tube being movable between a retracted position wherein the fluid inlet is positioned above a top of the reaction well and an extended position wherein the fluid inlet is positioned adjacent to a bottom of the reaction well;

a drive motor adapted to move the aspiration tube between the retracted and extended positions; and

a wash tube having a fluid outlet, said wash tube positioned to direct a flow of wash solution to impinge on said aspiration tube and spray the wash solution into said reaction well and induce an agitated scrubbing of a surface of said reaction well.

10. The apparatus of claim 9 further comprising a pressurized supply of wash solution in fluid communication with the wash tube.

11. The apparatus of claim 9, wherein the interior diameter of the aspiration tube is approximately 0.033 inch.

12. The apparatus of claim 9, wherein the reaction well is a microwell.

13. The apparatus of claim 9, further comprising a vacuum pump in communication with the aspiration tube to establish a regulated partial vacuum in the aspiration tube.

14. The apparatus of claim 9, wherein the aspiration tube is connected to an aspiration line, which line is further connected to a vacuum pump and controlled by a solenoid-operated liquid pump.

15. The apparatus of claim 9, wherein the aspiration tube is positioned substantially vertically and wherein the wash tube is positioned with respect to the aspiration tube at an angle of approximately 15°

.

16. The apparatus of claim 9, wherein the wash tube has an interior diameter of approximately 0.027 inch.

17. The apparatus of claim 10, wherein the pressurized supply of wash fluid includes a solenoid-operated liquid pump.

18. An apparatus for removing sample fluid from a reaction well, said apparatus comprising:

an elongated aspiration tube having a fluid inlet, the aspiration tube being movable between a retracted position wherein the fluid inlet is positioned above a top of the reaction well and an extended position wherein the fluid inlet is positioned adjacent to a bottom of the reaction well;

a vacuum pump in communication with the aspiration tube to establish a regulated partial vacuum in the aspiration tube;

a drive motor operatively connected to the aspiration tube to move the aspiration tube between the retracted and extended positions in coordination with the vacuum pump; and

a wash tube having a fluid outlet, said wash tube positioned to direct a flow of wash solution to impinge on said aspiration tube and spray the wash solution into said reaction well and induce an agitated scrubbing of a surface of said reaction well.

19. The apparatus of claim 18, wherein the apparatus is adapted to aspirate fluid from a plurality of adjacent reaction wells, further comprising a plurality of said aspiration tubes positioned generally parallel to one another, the fluid inlet of each of the aspiration tubes in their respective retracted positions being positioned above a top of one of said adjacent reaction wells.

20. The apparatus of claim 19, wherein each aspiration tube is positioned substantially vertically, the apparatus further comprising a plurality of said wash tubes, one wash tube being positioned with respect to one aspiration tube at an angle of approximately 15°

.

21. An apparatus for washing a reaction well, the apparatus comprising a moveable aspiration tube adapted to aspirate fluid from the reaction well and a wash tube having a fluid outlet, said wash tube positioned to direct a flow of wash solution to impinge on an exterior surface of said aspiration tube and spray the wash solution into said reaction well and induce an agitated scrubbing of a surface of said reaction well.