Macromolecule analysis employing nucleic acid encoding

1. A method for treating a plurality of polypeptides, comprising:

(a) providing a plurality of labeled polypeptides in a plurality of compartments, wherein (i) each polypeptide of the plurality of labeled polypeptides is labeled with a nucleic acid tag; (ii) each compartment comprises a plurality of nucleic acid compartment tags each comprising a barcode, which is the same within an individual compartment and different from barcodes of nucleic acid compartment tags of other compartments;

(b) for each polypeptide of the plurality of labeled polypeptides present in a compartment of the plurality of compartments, transferring a nucleic acid compartment tag of the plurality of nucleic acid compartment tags or a complement thereof to each nucleic acid tag of the polypeptide, thereby generating a plurality of recording tag-labeled polypeptides, wherein the transfer occurs via a primer extension and/or ligation, and each recording tag-labeled polypeptide comprises one or more recording tags each comprising the barcode or a complement thereof; and

(c) fragmenting the plurality of recording tag-labeled polypeptides to obtain a plurality of recording tag-labeled peptides, wherein each recording tag-labeled peptide of the plurality of recording tag-labeled peptides comprises a recording tag comprising the barcode or the complement thereof.

2. The method of claim 1 , further comprising releasing recording tag-labeled polypeptides of the plurality of recording tag-labeled polypeptides from the plurality of compartments.

3. The method of claim 1 , further comprising coupling recording tag-labeled peptides of the plurality of recording tag-labeled peptides to a solid support, wherein adjacent recording tag-labeled peptides coupled to the solid support are spaced apart from each other at an average distance of about 50 nm or greater.

4. The method of claim 3 , further comprising analyzing the recording tag-labeled peptides coupled to the solid support, wherein the analyzing comprises: (i) contacting the solid support with a plurality of binding agents capable of binding to the peptides coupled to the solid support; and (ii) following binding of a binding agent from the plurality of binding agents to a peptide coupled to the solid support, obtaining information regarding the binding agent, thereby analyzing the peptide.

5. The method of claim 1 , wherein each compartment of the plurality of compartments is a droplet.

6. The method of claim 1 , wherein each compartment of the plurality of compartments constitutes a surface of a bead.

7. The method of claim 1 , wherein in (a), the plurality of nucleic acid compartment tags is attached to a bead within a compartment or to a surface of the compartment.

8. The method of claim 1 , wherein before (a), each polypeptide of the plurality of labeled polypeptides is labeled with one or more nucleic acid tags by conjugating the nucleic acid tag to a ε-amine moiety of one or more lysine residues of the polypeptide.

9. The method of claim 1 , wherein in (a), two or more separate nucleic acid tags each comprises a universal priming sequence.

10. The method of claim 1 , wherein in (a), at least some of polypeptides of the plurality of labeled polypeptides are labeled with two or more separate nucleic acid tags.

11. The method of claim 1 , wherein in (a), each compartment tag of the plurality of nucleic acid compartment tags further comprises a unique molecular identifier (UMI).

12. A method for treating a polypeptide, comprising:

(a) providing a labeled polypeptide in a compartment, wherein the polypeptide is labeled with i) a nucleic acid barcode or a unique molecular identifier (UMI) tag, and ii) one or more nucleic acid tags distinct from the nucleic acid barcode or UMI tag;

(b) transferring the barcode or UMI tag or a complement thereof to each of the one or more nucleic acid tags attached to the polypeptide, wherein the transfer occurs via a primer extension and/or ligation, thereby generating a recording tag-labeled polypeptide comprising two or more separate recording tags each comprising the barcode or UMI tag or the complement thereof; and

(c) fragmenting the recording tag-labeled polypeptide to obtain a plurality of recording tag-labeled peptides, wherein each recording tag-labeled peptide of the plurality of recording tag-labeled peptides comprises the barcode or UMI tag or the complement thereof.

13. The method of claim 12 , further comprising coupling recording tag-labeled peptides of the plurality of recording tag-labeled peptides to a solid support, wherein adjacent recording tag-labeled peptides coupled to the solid support are spaced apart from each other at an average distance of about 50 nm or greater.

14. The method of claim 13 , further comprising analyzing the recording tag-labeled peptides coupled to the solid support, wherein the analyzing comprises: (i) contacting the solid support with a plurality of binding agents capable of binding to the peptides coupled to the solid support; and (ii) following binding of a binding agent from the plurality of binding agents to a peptide coupled to the solid support, obtaining information regarding the binding agent, thereby analyzing the peptide.

15. The method of claim 12 , wherein the barcode or UMI tag comprises identifying information regarding the polypeptide.

16. The method of claim 12 , wherein the plurality of recording tag-labeled peptides comprises at least two recording tag-labeled peptides.

17. The method of claim 12 , wherein before (a), the polypeptide is labeled with the nucleic acid barcode or UMI tag at an N-terminus or a C-terminus.

18. The method of claim 12 , wherein before (a), the polypeptide is labeled with the nucleic acid barcode or UMI tag at the N-terminus.

19. The method of claim 12 , wherein the nucleic acid barcode or UMI tag further comprises a priming sequence, and the one or more nucleic acid tags each comprises a complement of the priming sequence.

20. The method of claim 19 , wherein the transfer of the barcode or UMI tag or the complement thereof to each of the one or more nucleic acid tags in (b) comprises: i) amplifying the barcode or UMI tag or the complement thereof by a nucleic acid polymerization reaction, and ii) transferring the amplified barcode or UMI tag or the complement thereof to each of the one or more nucleic acid tags by primer extension and/or ligation.

21. A method for treating a plurality of polypeptides, comprising:

(a) providing a plurality of labeled polypeptides in a plurality of compartments, wherein each polypeptide of the plurality of labeled polypeptides is labeled with i) a nucleic acid barcode or a unique molecular identifier (UMI) tag, and ii) one or more nucleic acid tags, and wherein each compartment comprises, on average, fewer than a single polypeptide;

(b) for each polypeptide of the plurality of labeled polypeptides, transferring the barcode or UMI tag or a complement thereof to each of the one or more nucleic acid tags, wherein the transfer occurs via a primer extension reaction and/or ligation, thereby generating a plurality of recording tag-labeled polypeptides, wherein each recording tag-labeled polypeptide comprises two or more separate recording tags each comprising the barcode or UMI tag or the complement thereof; and

(c) fragmenting the plurality of recording tag-labeled polypeptides to obtain a plurality of recording tag-labeled peptides, wherein each recording tag-labeled peptide of the plurality of recording tag-labeled peptides comprises the barcode or UMI tag or the complement thereof.

22. The method of claim 21 , further comprising coupling recording tag-labeled peptides of the plurality of recording tag-labeled peptides to a solid support, wherein adjacent recording tag-labeled peptides coupled to the solid support are spaced apart from each other at an average distance of about 50 nm or greater.

23. The method of claim 21 , wherein each compartment of the plurality of compartments is a droplet.

24. The method of claim 23 , wherein the droplet is a nanoemulsion droplet.

25. The method of claim 23 , wherein before (b), the nucleic acid barcode or UMI tag is amplified inside the droplet by a nucleic acid polymerization reaction.

26. The method of claim 21 , wherein each compartment of the plurality of compartments constitutes a surface of a bead.

27. The method of claim 1 , wherein the plurality of polypeptides is a plurality of proteins, the plurality of recording tag-labeled polypeptides is a plurality of recording tag-labeled proteins, and the plurality of recording tag-labeled proteins is fragmented.