Apparatus and methods for on-chip monitoring of cellular reactions

• US 20030175944A1
• Filed: 03/18/2002
• Published: 09/18/2003
• Est. Priority Date: 03/18/2002
• Status: Active Grant

• Current Assignee: City University of Hong Kong
• Original Assignee: City University of Hong Kong
• Inventors: Yang, Jun, Yang, Mengsu, Li, Cheuk Wing
• Granted Patent: US 7,560,267 B2
• Time in Patent Office: Days
• US Class Current: 435/287.1
• CPC Class Codes: B01F 25/3141 with additional mixing means other than injector mixers
• CPC Class Codes: B01F 25/4321 the subflows consisting of at least two flat layers which are recombined, e.g. using means having restriction or expansion zones
• CPC Class Codes: B01F 25/433 Mixing tubes wherein the shape of the tube influences the mixing, e.g. mixing tubes with varying cross-section or provided with inwardly extending profiles
• CPC Class Codes: B01F 25/4332 Mixers with a strong change of direction in the conduit for homogenizing the flow
• CPC Class Codes: B01F 33/30 Micromixers
• CPC Class Codes: B01F 33/3039 with mixing achieved by diffusion between layers
• CPC Class Codes: B01L 2200/0668 Trapping microscopic beads
• 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 3/502746 characterised by the means for controlling flow resistance, e.g. flow controllers, baffles B01L3/502738 takes precedence
• CPC Class Codes: B01L 3/502776 specially adapted for focusing or laminating flows
• CPC Class Codes: G01N 1/38 Diluting, dispersing or mixing samples

Abstract

This invention relates to apparatus and methods for on-chip monitoring of cellular reactions, and in particular to such an apparatus and method that enables soft-docking of cells by using a dam wall that is parallel to the direction of fluid flow. The invention further relates to an apparatus and method capable of generating a controlled concentration gradient, and in particular a concentration gradient such that the cells are aligned in the direction of the concentration gradient after docking.

Claims

1. Apparatus for on-chip monitoring of cellular reactions comprising, a surface formed with a plurality of channels for fluid flow and means for supplying a cell bearing fluid to a first of said channels, wherein a second of said channels extends parallel to the first said channel for at least a part of their length and wherein the first and second channels are separated over said at least one part of their length by a wall defining a dam and over which fluid may flow from the first of said channels into the second of said two channels.

2. Apparatus as claimed in claim 1 wherein said two channels extend parallel to each other in a plurality of zones, and wherein in each said zone the said two channels are separated by a said wall member whereby a dam is formed in each said zone.

3. Apparatus as claimed in claim 1 wherein means are provided for supplying a cell bearing fluid to a first of said two channels at a first liquid pressure, and wherein means are provided for supplying a fluid to the second of said two channels at a second liquid pressure which is lower than the first liquid pressure.

4. Apparatus as claimed in claim 1 further comprising means for supplying a reagent to said first channel, and means for generating a concentration gradient of said reagent within said channel whereby said reagent concentration varies in the direction of fluid flow in said first channel.

5. Apparatus as claimed in claim 4 wherein said concentration gradient generating means comprises means for diluting the said reagent.

6. Apparatus as claimed in claim 5 wherein said dilution generating means comprises at least one dilution intersection wherein a diluting liquid is supplied to said first channel through at least one further channel.

7. Apparatus as claimed in claim 6 wherein means are provided for switching between first and second dilution modes by either supplying or not supplying a buffer fluid to said second channel while reagent is supplied to said first channel.

8. Apparatus as claimed in claim 7 wherein a primary dilution intersection is provided at a first location, and a secondary dilution intersection is provided at a second location, said first location being upstream of said second location in terms of the flow of reagent in said first channel.

9. Apparatus for on-chip monitoring of cellular reactions comprising, means for immobilising a plurality of viable cells in a line extending in a first direction, means for supplying a reagent to said cells, and means for forming a concentration gradient of said reagent along said line.

10. Apparatus for generating a concentration gradient of a reagent supplied to a device for on-chip monitoring of a cellular reaction, comprising a first channel for receiving said reagent, a second channel adjacent said first channel and said first and second channels being in fluid communication, at least one further channel for supplying a diluting fluid to said first channel, and means for selectively either supplying or not supplying a buffer solution to said second channel whereby said apparatus may operate in two dilution modes dependent on whether or not said buffer solution is supplied to said second channel.

11. Apparatus as claimed in claim 10 wherein said at least one further channel supplies diluting fluid to said first channel at a first dilution intersection, and wherein said apparatus further comprises another channel for supplying diluting fluid to said first channel at a second dilution intersection, said first intersection being upstream of said second intersection in terms of the flow of reagent in said first channel.

12. A method for on-chip monitoring of cellular reactions comprising, immobilising a plurality of viable cells in a line extending in a first direction, supplying a reagent to said cells, and forming a concentration gradient of said reagent along said line.

13. A method for immobilising cells in an apparatus for on-chip monitoring of cellular reactions comprising, providing said apparatus with first and second fluid channels formed for at least a part of their length parallel to each other and divided from each other in said at least part of their length by a wall defining a dam over which fluid may flow, supplying a cell bearing fluid to a first channel at a first liquid pressure, and supplying a liquid to said second channel at a second liquid pressure that is lower than said first liquid pressure.

14. A method for generating a concentration gradient of a reagent supplied to an apparatus for on-chip monitoring of cellular reactions comprising, supplying said reagent to a first channel, selectively supplying a buffer to a second channel adjacent said first channel and in fluid communication therewith, and supplying a diluting agent to said first channel at a dilution intersection.