Rapid and sensitive detection and quantification of analytes in complex samples using polymer-based methods
Provided herein, inter alia, are improved methods for detecting analytes, including proteins and nucleic acids. In some instances, the analytes are detected in complex matrices such as serum.
1. A method for detecting an analyte in a sample comprising combining a sample with (a) a first polymer conjugated to a first analyte-specific binding partner and (b) a second polymer conjugated to a second analyte-specific binding partner, under conditions that allow binding of the first and second analyte-specific binding partners to respective analytes, wherein the first and second analyte-specific binding partners are able to bind to a single analyte simultaneously,
detecting a complex formed by the binding of the first polymer and the second polymer to the single analyte in the sample, through their respective analyte-specific binding partners, using gel electrophoresis, wherein presence of the complex is indicative of presence of the single analyte in the sample,
wherein the sample is a blood, serum or urine sample, wherein the complex is detected in the presence of a nuclease inhibitor and a charged protein binding dye, and the single analyte is a protein or a peptide, and
wherein the first and second polymers are not bound to each other, directly or indirectly, prior to binding to the single analyte.
2. The method of claim 1 , wherein the first and second polymers are nucleic acids, and the sample and first and second polymers are combined in the presence of a nucleic acid binding dye, EDTA and a charged protein binding dye.
3. The method of claim 1 , wherein the sample is a serum sample.
4. The method of claim 1 , wherein the sample is a blood sample.
5. The method of claim 1 , wherein the sample is a filtered blood sample.
6. The method of claim 1 , wherein the sample is a lysed blood sample.
7. The method of claim 1 , wherein the charged protein binding dye is negatively charged.
8. The method of claim 1 , wherein the charged protein binding dye is positively charged.
9. The method of claim 1 , wherein the first and second analyte-specific binding partners are identical.
10. The method of claim 1 , wherein the first and second analyte-specific binding partners are different.
11. The method of claim 1 , wherein the first and second analyte-specific binding partners bind to an identical epitope that is present at least twice in the analyte.
12. The method of claim 1 , wherein the first and second analyte-specific binding partners are antibodies or antigen-binding antibody fragments.
13. A method for detecting an analyte in a sample comprising
combining a sample with (a) a first polymer conjugated to a first analyte-specific binding partner and (b) a second polymer conjugated to a second analyte-specific binding partner, under conditions that allow binding of the first and second analyte-specific binding partners to respective analytes, wherein the first and second analyte-specific binding partners are able to bind to a single analyte simultaneously,
detecting a complex formed by the binding of the first polymer and the second polymer to an analyte in the sample, through their respective analyte-specific binding partners, wherein presence of the complex is indicative of presence of the analyte in the sample,
wherein the complex is detected in the presence of a nuclease inhibitor and a charged protein binding dye,
wherein the first and second polymers are not bound to each other, directly or indirectly, prior to binding to the single analyte, and
wherein the nuclease inhibitor is EDTA, the analyte in the sample is Early Pregnancy Factor (EPF) and the sample is a urine sample.
14. The method of claim 13 , wherein the charged protein binding dye is negatively charged.
15. The method of claim 13 , wherein the charged protein binding dye is positively charged.
16. The method of claim 13 , wherein the first and second analyte-specific binding partners are different.
17. The method of claim 13 , wherein the first and second analyte-specific binding partners are identical.
18. The method of claim 13 , wherein the first and second analyte-specific binding partners bind to an identical epitope that is present at least twice in the analyte.
19. The method of claim 13 , wherein the first and second analyte-specific binding partners are antibodies or antigen-binding antibody fragments.
20. The method of claim 13 , wherein the first and second polymers are nucleic acids, and the sample and first and second polymers are combined in the presence of a nucleic acid binding dye, EDTA and a charged protein binding dye.