Method and apparatus for liquid addition and aspiration in automated immunoassay techniques

• US 4,803,050 A
• Filed: 07/22/1986
• Issued: 02/07/1989
• Est. Priority Date: 07/22/1985
• Status: Expired due to Fees

• Current Assignee: Sequoia-Turner Corp. (Abbott Laboratories Incorporated)
• Original Assignee: Sequoia-Turner Corp. (Abbott Laboratories Incorporated)
• Inventors: Mack, Daniel R.
• Primary Examiner(s): Castel, Benoit
• Assistant Examiner(s): Jordan, Richard D.
• Application Number:
  US06/888,848
• Time in Patent Office: 931 Days
• Field of Search: 23/864.24, 141/270, 141/283, 422/63-65, 422/67, 422/100, 436/47, 436/49
• US Class Current: 422/65
• CPC Class Codes: G01N 2035/1025 Fluid level sensing
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 35/026 having blocks or racks of reaction cells or cuvettes
• CPC Class Codes: G01N 35/1083 with one horizontal degree of freedom
• CPC Class Codes: Y10T 436/113332 with conveyance of sample along a test line in a container or rack

Abstract

Apparatus and method for adding liquid to, aspirating liquid from, a rack of reaction tubes wherein a rack and carriage-dependent probes are made to move relative each other in the horizontal and vertical planes. The method calls for performing the first half of a wash sequence on tube located at x row, y column, then completing the sequence on tube at (x-1) row, y column, and returning to the tube at x row, (y+1) column to initiate the first half of the sequence. This "backtracking" of probes permits an incubation-soak period without cumulatively extending the total rack processing time.

Claims

1. A method for adding liquid to, and aspirating liquids from, reaction tubes disposed in rack comprising the steps of:

providing reaction tubes disposed in a rack, said rack having n rows in a first horizontal x-direction and m columns in a second horizontal y-direction, perpendicular to the x-direction;

a liquid probe depended from a carriage above said rack of tubes, said probe selectively moveable along its longitudinal axis relative to said carriage and perpendicular to the rack horizontal plane;

means for moving said carriage in the x-direction or y-direction;

means for selectively registering the liquid probe with a row of tubes in said rack; and

, control means for selecting and effecting absolute and relative movement of the carriage, probe and rack;

introducing a controlled, timed, tube-dependent pause in a sequence for adding liquid to, and aspirating liquid from, a rack of reaction tubes by controlling the carriage and liquid probe movement so that

for each of y=1 to m columns,

a. liquid is added to tube in x row, y column;

b. previously-added liquid from tube in (x-1) row, y column is aspirated;

c. carriage, rack and probe are returned to register said probe with the tube in x row, (y+1) column;

wherein x is between 1 and n.

2. The method of claim 1 wherein said liquid is detergent solution for use in immunoassays.

3. The method of claim 1 wherein said reaction tubes contain a solid support upon which is bound a member of an immunological pair.

4. An apparatus for adding liquid to, and aspirating liquids from, tubes which comprises:

a rack of reaction tubes, said rack having n rows in a first horizontal x-direction and m columns in a second horizontal y-direction, perpendicular to the x-direction, in a rectangular matrix, wherein x=1 to n rows, and y=1 to m columns;

means for receiving and positioning said rack;

a carriage above said rack;

at least one liquid probe depended from said carriage above said rack and selectively moveable along said probe longitudinal axis relative to said carriage;

means for selectively moving said carriage in the x-direction or y-direction;

means for selectively registering the liquid probe with a row of tubes in said rack;

control means for actuating said rack positioning means to move said rack discrete distances in the y-direction substantially equivalent to one column of tubes, relative to said probe, and for selecting movement of said carriage in the x-direction or y-direction; and

,

second control means, for each of x=1 to n rows and y=1 to m columns, for first delivering liquid from said liquid probe to a tube located in x row, y column, for aspirating through the probe previously added liquid in a tube located at (x-1) row, y column, and for returning said carriage, rack and probe to register said probe with the tube in x row, (y+1) column.

5. The apparatus of claim 4 wherein said liquid probe has a relatively large outer diameter, as compared to the reaction tube inner diameter, to enable good aspiration and vacuum drying.

6. The apparatus of claim 4 further comprising a first and second liquid probe wherein the first liquid probe dispenses detergent solution and the second liquid probe aspirates detergent solution.