Sandwich assays in droplets
The invention generally relates to performing sandwich assays in droplets. In certain embodiments, the invention provides methods for detecting a target analyte that involve forming a compartmentalized portion of fluid including a portion of a sample suspected of containing a target analyte and a sample identifier, a first binding agent having a target identifier, and a second binding agent specific to the target analyte under conditions that produce a complex of the first and second binding agents with the target analyte, separating the complexes, and detecting the complexes, thereby detecting the target analyte.
1. A method comprising:
incubating a target analyte with binding agents, wherein the binding agents comprise binders linked to oligonucleotides,
wherein each binding agent is provided with barcode sequences that include a target analyte identifier and a unique identifier unique to the binding agent;
binding one of the binding agents to the target analyte; and
sequencing the barcode sequences to detect the target analyte.
2. The method of claim 1 , wherein the binders are antibodies.
3. The method of claim 1 , further comprising releasing the barcode sequences from the binding agent prior to the sequencing step.
4. The method of claim 1 , wherein the target analyte is a protein.
5. The method of claim 4 , wherein the protein comprises a cell surface protein or a protein secreted by cells.
6. The method of claim 4 , wherein the binders are aptamers.
7. The method of claim 1 , wherein the target analyte is protein from cells in a sample and the method includes isolating the cells into partitions.
8. The method of claim 7 , wherein each barcode sequence further includes an identifier specific for one of the partitions.
9. The method of claim 8 , wherein the identifier specific for the partition is detected to associate the detection of the target analyte with the partition.
10. The method of claim 7 , further comprising lysing the cells in the partitions.
11. A method comprising:
incubating a target analyte with binding agents, wherein the binding agents comprise antibodies linked to oligonucleotides, wherein the target analyte is a protein;
binding one of the binding agents to the target analyte, wherein each binding agent is provided with barcode sequences that include a target analyte identifier sequence and a unique identifier sequence unique to the binding agent; and
sequencing the barcode sequences to detect the target analyte.
12. The method of claim 11 , further comprising releasing the barcode sequences from the binding agent prior to the sequencing step.
13. The method of claim 12 , wherein the protein comprises a cell surface protein or a protein secreted by cells.
14. The method of claim 11 , wherein the target analyte is protein from cells in a sample and the method includes isolating the cells into partitions.
15. The method of claim 14 , wherein each barcode sequence further includes an identifier specific for one of the partitions.
16. The method of claim 15 , wherein the identifier specific for the partition is detected to associate the detection of the target analyte with the partition.
17. The method of claim 14 , further comprising lysing the cells in the partitions.