DNA-Encoding to Improve Performance and Allow Parallel Evaluation of the Binding Characteristics of Multiple Antibodies in a Surface-Bound Immunoassay Format

High affinity capture agents against protein targets are essential components for immunoassays, regardless of specific analysis format. Here, we describe the use of DNA-encoded antibodies for rapidly screening the kinetic and equilibrium binding properties of twelve commercial antibodies in a parallel analysis format using a multiplexed array of microring optical resonators. We show that DNA-encoding offers advantages in terms of antigen binding capacity, compared to covalently tethered antibodies; we also demonstrate that this linkage modality facilitates the rapid self-assembly of multiplexed arrays on account of complementarity between the DNA sequences on the antibodies and sensor array, respectively. Furthermore, DNA-encoded antibodies also allow for sensor array regeneration and reprogramming, as chaotropic agents can be used to disrupt the DNA DNA duplexes that link the capture agents to the sensor without harming the underlying DNA on the surface, which can subsequently be reloaded with antibodies either targeting the same or different antigens.