Methods, devices, and systems for monitoring time dependent reactions

• US 6,589,729 B2
• Filed: 01/31/2001
• Issued: 07/08/2003
• Est. Priority Date: 02/04/2000
• Status: Expired due to Term

• Current Assignee: Caliper Holdings Incorporated
• Original Assignee: Caliper Holdings Incorporated
• Inventors: Chan, Samuel D. H., Chow, Andrea W., Chien, Ring-Ling, Wang, Benjamin N.
• Primary Examiner(s): GITOMER, RALPH J
• Application Number:
  US09/774,531
• Publication Number:
  US 20010051338A1
• Time in Patent Office: 888 Days
• Field of Search: 435/7.2, 435/287.3, 435/4, 435/288.2, 435/288.5, 435/286.1
• US Class Current: 435/4
• CPC Class Codes: B01D 15/3857 Reaction chromatography
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0867 Multiple inlets and one sample wells, e.g. mixing, dilution
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/084 Passive control of flow resistance
• 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: G01N 2021/6482 Sample cells, cuvettes
• CPC Class Codes: G01N 21/64 Fluorescence; Phosphorescence
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/75 Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated systems in which material is burnt in a flame or plasma G01N21/72, G01N21/73
• CPC Class Codes: G01N 30/02 Column chromatography

Abstract

Methods for monitoring time dependent reactions that comprise providing a flow channel, typically microscale in dimension, flowing at least two reagents into the flow channel and varying the flow rate of the mixture through the flow channel. By increasing and/or decreasing the flow rate of the reagent mixture from the point of mixing to the point of detection, one alters the amount of reaction time, allowing monitoring reaction kinetics over time.

Claims

1. A method of monitoring a time dependent reaction, comprising:

(i) introducing at least a first reagent into a first flow channel;

(ii) initiating a reaction involving the at least first reagent, thereby producing a first reaction mixture;

(iii) transporting the first reaction mixture at a first flow rate along the first flow channel past a detection zone;

(iv) detecting an extent of the reaction involving the at least first reagent at the detection zone at said first flow rate;

(v) varying a flow rate of the first reaction mixture along the first flow channel to a second flow rate which is different from said first flow rate; and

(vi) detecting an extent of the reaction involving the at least first reagent at the detection zone at said second flow rate, thereby providing a reaction time course for the reaction for a plurality of different reaction times.

2. The method of claim 1, wherein the step of initiating the reaction of the first reagent comprises mixing a second reagent with the first reagent to form the reaction mixture.

3. The method of claim 2, wherein at least one of the first and second reagents comprises a cell suspension.

4. The method of claim 2, wherein at least one of the first and second reagents comprises at least one member of a specific binding pair.

5. The method of claim 2, wherein the reaction between the first and second reagents produces an optically detectable signal.

6. The method of claim 5, wherein the optically detectable signal comprises a fluorescent signal.

7. The method of claim 6, wherein the fluorescent signal comprises an increase or decrease in a level of fluorescence in the first flow channel.

8. The method of claim 6, wherein the fluorescent signal comprises a change in an amount of depolarized fluorescence within the first flow channel.

9. The method of claim 2, wherein the first flow channel and at least one of a source of the first reagent and a source of the second reagent are disposed in an integrated body structure.

10. The method of claim 2, wherein the step of varying the flow rate comprises varying an applied pressure differential along the length of the at least first flow channel.

11. The method of claim 10, wherein the step of varying an applied pressure differential along a length of the first flow channel comprises varying a vacuum applied at one end of the first flow channel.

12. The method of claim 10, wherein the step of varying an applied pressure differential along a length of the first flow channel comprises varying a positive pressure applied at one end of the first flow channel.

13. The method of claim 2, further comprising:

providing at least a second flow channel;

introducing the first and second reagents into the second flow channel whereupon the first and second reagents mix to form a second reaction mixture, at least one of the first or second reagent being present in the second reaction mixture at a concentration different from its concentration in the first reaction mixture;

varying a flow rate of the second reaction mixture along the second flow channel; and

monitoring a result of an interaction between the first and second reagents.

14. The method of claim 13, wherein the steps of varying the flow rate along the first flow channel and varying the flow rate along the second flow channel comprise concurrently applying a varying pressure differential along a length of the first and second flow channels.

15. The method of claim 14, wherein the first and second flow channels are in fluid communication with a common port, and wherein the step of concurrently applying a pressure differential comprises applying a positive pressure or vacuum to the common port.

16. The method of claim 2, further comprising:

providing at least a second flow channel;

introducing third and fourth reagents into the second flow channel whereupon the third and fourth reagents mix to form a second reaction mixture, at least one of the third and fourth reagents being different from the first and second reagents;

varying a flow rate of the second reaction mixture along the second flow channel; and

monitoring a result of an interaction between the third and fourth reagents.

17. The method of claim 2, further comprising:

providing at least a second flow channel, the second flow channel having a flow resistance that is different from a flow resistance of the first flow channel;

introducing the first and second reagents into the second flow channel, whereupon the first and second reagents mix to form a second reaction mixture;

varying a flow rate of the second mixture along the second flow channel; and

monitoring a result of an interaction between the first and second reagents in the second reaction mixture.

18. The method of claim 17, wherein the steps of varying the flow rate of the first reaction mixture along the first flow channel and the second reaction mixture along the second flow channel comprises applying a single pressure differential across a length of the first and second flow channels, the different flow resistance of the second flow channel from the first flow channel producing a different flow rate of the second reaction mixture through the second flow channel than for the first reaction mixture through the first flow channel.

19. The method of claim 18, wherein the first and second flow channels are fluidly connected to a common port, and the step of varying the flow rate of the first reaction mixture along the first flow channel and the second reaction mixture along the second flow channel comprises applying a positive pressure or vacuum to the common port to move the first and second reaction mixtures through the first and second flow channels, respectively.

20. The method of claim 1, further comprising repeating steps (v) and (vi) at least once at at least a third flow rate which is different from said first and second flow rates to determine the reaction time course for at least three different reaction times.

21. The method of claim 20, further comprising calculating a kinetic curve of the reaction based on the determined reaction time course.

22. The method of claim 1, wherein said first flow rate is faster than said second flow rate.

23. The method of claim 1, wherein said first flow rate is slower than said second flow rate.