DNA-antigen exchange and amplification
Methods for imaging are described, including, but not limited to a method comprising: (1) contacting a sample being tested for the presence of one or more targets with one or more target-specific binding partners, wherein each target-specific binding partner is linked to a docking strand, and wherein target-specific binding partners of different specificity are linked to different docking strands, (2) optionally removing unbound target-specific binding partners, (3) contacting the sample with antigen-bound imager strands and antigen-specific binding partners linked (directly or indirectly) to optical labels, wherein the antigen-bound imager strands have complementarity to a docking strand, directly or indirectly, and wherein each antigen-specific binding partner is linked to one or more optical labels, and wherein antigen-specific binding partners of different specificity are linked to distinct optical labels, (4) optionally removing unbound antigen-bound imager strands and/or antigen-specific binding partners, (5) imaging the sample to detect bound labeled antigen-specific binding partners, (6) optionally removing/extinguishing signal from the optical labels, and (7) optionally repeating steps (1)-(7), or any subset thereof.
1. A method comprising:
(1) contacting a sample being tested for the presence of one or more targets with one or more target-specific binding partners, wherein each target-specific binding partner is linked to a first docking strand, and wherein target-specific binding partners of different specificity are linked to different docking strands,
(2) optionally removing unbound target-specific binding partners,
(3) contacting the sample with antigen-bound imager strands and antigen-specific binding partners,
wherein the antigen-bound imager strands have complementarity to the first docking strand, directly or indirectly, and
wherein each antigen-specific binding partner is linked to at least one second docking strand, and wherein the antigen specific binding partner binds to the antigen of the antigen-bound imager strand;
(4) optionally removing unbound antigen-bound imager strands and/or antigen specific binding partners,
(5) increasing the number of second docking strands by a DNA amplification reaction and labeling of the at least one second docking strand using an optical label,
(6) imaging the sample to detect bound labeled antigen-specific binding partners,
(7) optionally extinguishing the signal from the optical label, and
(8) optionally repeating steps (1)-(7), or any subset thereof.
2. The method of claim 1 , wherein the first docking strand and the at least one second docking strand have a different sequence.
3. The method of claim 1 , wherein the first docking strand and the at least one second docking strand have the same sequence.
4. The method of claim 1 , wherein the at least one second docking strand is directly labeled using labeled nucleotides in the DNA amplification reaction.
5. The method of claim 4 , wherein the labeled nucleotides are fluorescently-labeled nucleotides.
6. The method of claim 1 , wherein the at least one second docking strand is labeled using a labeled nucleic acid that binds thereto.
7. The method of claim 1 , wherein the DNA amplification reaction comprises rolling circle amplification.
8. The method of claim 1 , wherein the DNA amplification reaction comprises hybridization chain reaction.
9. The method of claim 1 , wherein the DNA amplification reaction comprises hairpin-based concatemerization (including dendrimerization) reaction.