Microfluidic devices
The present invention provides novel microfluidic substrates and methods that are useful for performing biological, chemical and diagnostic assays. The substrates can include a plurality of electrically addressable, channel bearing fluidic modules integrally arranged such that a continuous channel is provided for flow of immiscible fluids.
1. A method of analyzing a compound released from a cell, the method comprising:
providing a microfluidic substrate comprising an inlet module comprising a first inlet channel comprising a plurality of cells in aqueous solution and a second inlet channel comprising a plurality of primers in aqueous solution;
flowing the aqueous solutions together to form a combined aqueous solution, and flowing the combined aqueous solution through a nozzle into a reservoir comprising an oil, thereby extruding a plurality of droplets of aqueous solution into the reservoir, each droplet comprising primers and at least one cell from the plurality of cells;
incubating the plurality of the droplets off of the microfluidic substrate;
causing at least one secreted substance to be released from the cell in each droplet; and
conducting a homogenous assay with the primers on the secreted substance, the homogenous assay being conducted inside each of the plurality of droplets.
2. The method of claim 1 , wherein the cell is a bacterium cell, a fungal cell, a plant cell, or an animal cell.
3. The method of claim 1 , wherein each of the plurality of droplets in the providing step comprises a substrate for an enzyme.
4. The method of claim 3 , wherein the enzyme is conjugated to an antibody.
5. The method of claim 1 , wherein each of the plurality of droplets in the providing step further comprises a labeled compound.
6. The method of claim 1 , wherein the primers are bound to a bead.
7. The method of claim 1 , wherein the primers are barcoded.
8. The method of claim 1 , wherein each of the plurality of droplets in the providing step comprises reagents for an amplification reaction.
9. The method of claim 1 , wherein the secreted substance comprises a nucleic acid.
10. The method of claim 1 , wherein the homogenous assay comprises amplification.
11. The method of claim 10 , wherein amplification comprises PCR, QPCR, or rolling circle amplification.
12. The method of claim 5 , wherein the labeled compound comprises a dye.
13. The method of claim 1 , further comprising lysing the cell in each droplet before the conducting step.
14. The method of claim 1 , wherein the oil comprises a surfactant.
15. The method of claim 1 , further comprising breaking the droplets to release a product of the homogenous assay.
16. The method of claim 15 , further comprising sequencing the product of the homogenous assay.