Sample evaporative control

• US 6,627,406 B1
• Filed: 05/10/2000
• Issued: 09/30/2003
• Est. Priority Date: 05/11/1999
• Status: Expired due to Term

• Current Assignee: Monogram Biosciences, Inc. (Laboratory Corporation Of America Holdings)
• Original Assignee: Aclara Biosciences, Inc (Laboratory Corporation Of America Holdings)
• Inventors: Gibbons, Ian, Singh, Sharat, Ullman, Edwin F., Boone, Travis, Bjornson, Torleif Ove, Xiao, Vivian, Hooper, Herbert H.
• Primary Examiner(s): Ponnaluri, Padmashri
• Assistant Examiner(s): TRAN, MY CHAU T
• Application Number:
  US09/568,786
• Time in Patent Office: 1,238 Days
• Field of Search: 422/55, 422/58, 422/68.1, 422/82.01, 422/101, 435/287.1, 435/288.4, 435/288.5, 435/7.1, 435/7.94, 436/514, 436/518, 436/535, 436/149, 436/150, 436/151
• US Class Current: 435/7.1
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01J 19/16 Preventing evaporation or oxidation of non-metallic liquids by applying a floating layer, e.g. of microballoons in storage tanks B65D90/42
• CPC Class Codes: B01J 2219/00317 Microwell devices, i.e. having large numbers of wells
• CPC Class Codes: B01L 2200/0642 Filling fluids into wells by specific techniques
• CPC Class Codes: B01L 2200/142 Preventing evaporation
• CPC Class Codes: B01L 2300/0861 Configuration of multiple channels and/or chambers in a single devices
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 3/5025 for parallel transport of multiple samples
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/502723 characterised by venting arrangements
• CPC Class Codes: C40B 60/14 for creating libraries
• CPC Class Codes: G01N 1/34 Purifying; Cleaning processes or apparatus for extracting or separating nucleic acids from biological samples C12N15/1003
• CPC Class Codes: G01N 2035/00237 Handling microquantities of analyte, e.g. microvalves, capillary networks
• CPC Class Codes: G01N 2035/00287 movable lid/cover for sample or reaction tubes

Abstract

Devices and methods are provided using microfluidic devices for manipulating small volumes and determining a variety of chemical and physical events. The devices rely upon an opening to the atmosphere of a small volume in a zone, where a sample is placed in the zone where evaporation can occur. The zone is maintained in contact with a liquid medium that serves to replenish the liquid in the zone and maintain the composition of the mixture in the zone substantially constant. The diffusion of components in the zone is restricted during the course of the determination by the liquid flux into the zone.

Claims

1. A method for performing operations in small volumes with a volatile solvent, said method comprising:

adding a component for said operation to a liquid zone having (i) an exposed opening to the atmosphere, (ii) an interior border whereby a meniscus is created at said border which is disposed within the zone that is spaced from the exposed opening, and (iii) containing said volatile solvent subject to evaporation;

wherein said liquid zone is in contact with a replenishing medium inma capillary channel; and

maintaining a sample volume in said zone during said operation as said solvent undergoes evaporation by replenishing said sample volume with said replenishing medium from said capillary channel.

2. A method according to claim 1, wherein said capillary is connected to a reservoir of said replenishing medium.

3. A method according to claim 1, during said adding step, said liquid zone is in a well through a wall of said capillary channel, optionally at least a portion of the wall of said well is non-wettable, and said capillary channel is connected to two reservoirs.

4. A method according to claim 1, wherein said liquid zone is expressed from the end of said capillary channel.

5. A method according to claim 1, wherein said capillary channel is at least partially hydrophilic.

6. A method according to claim 1, wherein the total volume of liquid in said liquid zone is not more than about 5 μ

l.

7. A method according to claim 1, wherein after said operation, at least one component in said liquid zone is transferred through a capillary channel to an electrokinesis system.

8. A method according to claim 1, wherein said operation is an enzyme assay.

9. A method according to claim 1, wherein said operation is a ligand-receptor binding assay.

10. A method according to claim 1, wherein said operation is a reporter gene assay.

11. A method according to claim 1, during said adding step said interior border is formed as a result of border of a wettable and a non-wettable surface in said zone.

12. A method according to claim 1, during said adding step said interior border is formed as a result of a sharp change of direction of the wall of the zone.

13. A method according to claim 1, during said adding step said interior border is formed as a result of a hydraulic head.