Method and apparatus for handling small volume fluid samples

• US 20050035143A1
• Filed: 08/15/2003
• Published: 02/17/2005
• Est. Priority Date: 08/15/2003
• Status: Active Grant

• Current Assignee: Protedyne Corporation (Laboratory Corporation Of America Holdings)
• Original Assignee: Protedyne Corporation (Laboratory Corporation Of America Holdings)
• Inventors: Massaro, Peter, Geldhof, Benjamin F.
• Granted Patent: US 7,097,070 B2
• Time in Patent Office: Days
• US Class Current: 222/1
• CPC Class Codes: B01L 2300/0838 Capillaries
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/0633 with moving parts
• CPC Class Codes: B01L 2400/0666 Solenoid valves
• CPC Class Codes: B01L 3/021 Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
• CPC Class Codes: B01L 3/0241 Drop counters; Drop formers making arrays for combinatorial libraries B01J19/0046; automation of dispensing for analysis G01N35/10
• CPC Class Codes: G01N 2035/1034 Transferring microquantities of liquid
• CPC Class Codes: G01N 35/1016 Control of the volume dispensed or introduced

Abstract

A small-volume sample handling system includes a chamber with first and second portions. A conduit having a flow control valve may be fluidly coupled to the first portion. A pressure in the second portion may be adjusted so that liquid samples can be aspirated and dispensed in a needle coupled to the valve in response to opening of the valve. The first and second portions of the chamber may be separated by a diaphragm.

Claims

1. A system for handling fluid samples comprising:

a fluid reservoir having a diaphragm separating a liquid portion of the reservoir from a gas portion of the reservoir;

a solenoid valve having an input and an output, the solenoid valve adapted open and close a passage between the input and the output;

a conduit fluidly coupling the liquid portion of the reservoir to the input of the solenoid valve; and

a sample handling channel in fluid communication with the output of the solenoid valve;

wherein a pressure in the gas portion of the reservoir controls the sample handling channel to aspirate and dispense a fluid sample in response to opening of the passage in the solenoid valve.

2. The system of claim 1, further comprising:

a variable pressure supply that provides a controlled gas pressure in the gas portion of the reservoir.

3. The system of claim 1, wherein the variable pressure supply includes a servo-controlled regulator that controls a gas pressure in the gas portion of the reservoir.

4. The system of claim 1, wherein the variable pressure supply includes a vacuum source that provides a gas pressure below an ambient pressure and a gas supply that provides a gas pressure above an ambient pressure.

5. The system of claim 1, further comprising:

a controller that controls the operation of the solenoid valve to open and close the passage and controls the gas pressure in the gas portion of the reservoir.

6. The system of claim 5, wherein the solenoid valve is controlled to open and close at a high frequency.

7. The system of claim 1, wherein the sample handling channel and the solenoid valve are constructed and arranged to aspirate and dispense nanoliter-sized liquid samples.

8. The system of claim 1, wherein the sample handling channel includes a jeweled needle.

9. The system of claim 1, further comprising:

a plurality of sample handling channels each associated with a corresponding solenoid valve in fluid communication with the liquid portion of the reservoir, the sample handling channels arranged in a pattern to cooperate with wells in a microtiter tray.

10. The system of claim 9, further comprising:

a robotic device that moves the sample handling channels relative to a work surface so liquid samples are aspirated and dispensed in desired locations.

11. The system of claim 1, wherein the diaphragm includes a sheet of elastomeric material.

12. A liquid sample handling apparatus comprising:

a fluid supply;

a variable pressure supply constructed and arranged to provide a negative pressure and a positive pressure relative to an ambient pressure;

a chamber having a flexible diaphragm separating first and second portions in the chamber, the first portion being in fluid communication with the fluid supply and the second portion being in communication with the variable pressure supply;

a valve in fluid communication with the first portion of the chamber; and

a needle in fluid communication with the valve;

wherein a negative pressure in the second portion causes the needle to aspirate a fluid sample when the valve is open, and a positive pressure in the second portion causes the needle to dispense a fluid sample when the valve is open.

13. The system of claim 12, wherein the variable pressure supply includes a servo-controlled regulator that controls a gas pressure in the second portion of the chamber.

14. The system of claim 13, wherein the variable pressure supply includes a vacuum source that provides a gas pressure below an ambient pressure and a gas supply that provides a gas pressure above an ambient pressure.

15. The system of claim 12, further comprising:

a controller that controls the operation of the valve to open and close and controls the pressure in the second portion of the chamber.

16. The system of claim 12, wherein the valve is a solenoid valve.

17. The system of claim 12, wherein the needle and the valve are constructed and arranged to aspirate and dispense nanoliter-sized liquid samples.

18. The system of claim 12, further comprising:

a plurality of needles each associated with a corresponding valve in fluid communication with the first portion of the chamber, the needles arranged in a pattern to cooperate with wells in a microtiter tray.

19. The system of claim 18, further comprising:

a robotic device that moves the needles relative to a work surface so liquid samples are aspirated and dispensed in desired locations.

20. The system of claim 12, wherein the flexible diaphragm includes a sheet of elastomeric material.

21. A method of handling liquid samples using a robotically-manipulated tool, the method comprising:

fluidly coupling a sample handling channel with a first end of a conduit having a valve controllable to open and close a fluid flow passage along the conduit;

fluidly coupling a second end of the conduit opposite the first end to a liquid portion of a reservoir, the liquid portion of the reservoir being separated from a gas portion of the reservoir;

adjusting a pressure in the gas portion of the reservoir so liquid in the liquid portion of the reservoir is urged to flow into the conduit and opening the valve so that a fluid sample is dispensed from the sample handling channel; and

adjusting a pressure in the gas portion of the reservoir so liquid in the conduit is urged to flow into the liquid portion of the reservoir and opening the valve so that a fluid sample is aspirated by the sample handling channel.

22. A method of handling liquid samples using a robotically-manipulated tool, the method comprising:

raising a gas pressure in a reservoir so that fluid contained in the reservoir is urged to move out of the reservoir and into a conduit connected to the reservoir;

opening a valve that controls flow through the conduit;

dispensing a fluid sample from a sample handling channel fluidly coupled to the conduit;

lowering a gas pressure in the reservoir so that fluid contained in the conduit connected to the reservoir is urged to move into the reservoir;

opening a valve that controls flow through the conduit; and

aspirating a fluid sample into the sample handling channel.