Flow chamber and analyte detection method
A flow chamber and method for detecting the presence of one more cell produced analytes under flow conditions. The flow chamber includes two compartments separated by a permeable membrane on which a plurality of cells may be positioned. The permeable membrane shields one or more analyte sensors positioned one compartment from the convective transport forces of a fluid flow within the other compartment to allow reliable and accurate detection of cell-produced analytes and determination of the concentration of cell-produced analytes.
1. A flow chamber for detecting an analyte comprising:
a first compartment, wherein said first compartment comprises:
a fluid inlet and a fluid outlet for allowing a fluid to flow through said first compartment;
a second compartment;
a first analyte sensor positioned within said second compartment for detecting an analyte produced by cells located in said first compartment;
a permeable membrane, wherein said permeable membrane comprises:
a first surface that is exposed to fluid flow in said first compartment; and
a second surface in said second compartment,
wherein said permeable membrane separates said first compartment from said second compartment, and said permeable membrane has a pore size in a range of from about 0.1 μm to about 12 μm and a porosity of no more than 0.14;
and a flow rate controller for controlling flow of a fluid between said fluid inlet and said fluid outlet in said first compartment in a direction substantially parallel to a surface of said permeable membrane, said flow rate controller being configured to cycle said fluid flow rate between a control flow rate and a plurality or different higher flow rates each of the higher flow rates exerting a different shear stress on the surface of the membrane in said first compartment.
2. The flow chamber of claim 1 , wherein said first analyte sensor is positioned at a known predetermined distance from said first surface of said membrane.
3. The flow chamber of claim 2 , wherein said predetermined distance is about 5 μm to about 50 μm.
4. The flow chamber of claim 1 , wherein a distal end of said first analyte sensor contacts said second surface of said membrane.
5. The flow chamber of claim 1 , wherein said second compartment comprises a fluid inlet and a fluid outlet to permit rinsing of said second compartment with a fluid.
6. The flow chamber of claim 1 , wherein said first analyte sensor is adapted to detect a small molecule selected from the group consisting of: dissolved gases, ions, sugars, nucleotides, proteins and lipids.
7. The flow chamber of claim 1 , further comprising a second analyte sensor positioned within said first compartment, wherein said first and second analyte sensors are adapted to detect different analytes.
8. The flow chamber of claim 1 , further comprising a sensor holder associated said second compartment and said first analyte sensor for positioning said first analyte sensor in said second compartment.
9. The flow chamber of claim 1 , wherein said second compartment is a substantially enclosed internal space having a volume less than about 1 mL.
10. The flow chamber of claim 1 , wherein the exerted shear stresses exerted by the fluid flow rate is within a range of 0 to about 200 dyn/cm 2 .
11. The flow chamber of claim 1 , wherein the exerted shear stresses correspond to a series of step changes in the flow rate.
12. The flow chamber of claim 11 , wherein the series of step changes in flow rate correspond to shear stresses within the range of 1 to 20 dyn/cm 2 .
13. A method for detecting an analyte using a flow chamber comprising:
positioning a plurality of cells within the flow chamber of claim 1 on said first surface of the permeable membrane;
flowing a fluid through said first compartment; and
detecting, in said first compartment, one more analytes produced by said plurality of cells.
14. The method of claim 13 , wherein said permeable membrane allows for passage of said analyte and wherein said analyte is produced by said plurality of cells.
15. The flow chamber of claim 13 , wherein the exerted shear stresses exerted by the fluid flow rate is within a range of 0 to about 200 dyn/cm 2 .
16. The flow chamber of claim 13 , wherein the exerted shear stresses correspond to a series of step changes in the flow rate.
17. The flow chamber of claim 13 , wherein the series of step changes in flow rate correspond to shear stresses within the range of 1 to 20 dyn/cm 2 .
18. A flow chamber for detecting an analyte comprising:
a first compartment, wherein said first compartment comprises:
a fluid inlet and fluid outlet for allowing a fluid to flow through said first compartment;
a second compartment;
an analyte sensor positioned within said second compartment for detecting an analyte produced by cells located in said first compartment; and
a permeable membrane for allowing passage of an analyte from said first compartment to said second compartment,
wherein said analyte sensor is positioned at a known distance from a surface of said permeable membrane, and said permeable membrane has a pore size in a range of from about 0.1 μm to about 12 μm and a porosity no more than 0.14;
and a flow rate controller for controlling flow of a fluid between said fluid inlet and said fluid outlet in said first compartment in a direction substantially parallel to a surface of said permeable membrane, said flow rate controller being configured to cycle said fluid flow rate between a control flow rate and a plurality of different higher flow rates each of the higher flow rates exerting a different shear stress on the surface of the membrane in said first compartment.
19. The flow chamber of claim 18 , wherein first analyte sensor is removably fixed in place by a fastener.
20. The flow chamber of claim 18 , wherein said predetermined distance is about 5 μm to about 50 μm.