Facile Preparation of Stable Antibody-Gold Conjugates and Application to Affinity-Capture Self-Interaction Nanoparticle Spectroscopy.

Protein-nanoparticle conjugates are widely used for conventional applications such as immunohistochemistry and biomolecular detection as well as emerging applications such as therapeutics and advanced materials. Nevertheless, it remains challenging to reproducibly prepare stable protein-nanoparticle conjugates with highly similar optical properties. Here we report an improved physisorption method for reproducibly preparing stable antibody-gold conjugates at acidic pH using polyclonal antibodies from a wide range of species (human, goat, rabbit, mouse, and rat).

Discovery of highly soluble antibodies prior to purification using affinity-capture self-interaction nanoparticle spectroscopy.

Self-association of monoclonal antibodies (mAbs) at high concentrations can result in developability challenges such as poor solubility, aggregation, opalescence and high viscosity. There is a significant unmet need for methods that can evaluate self-association propensities of concentrated mAbs at the earliest stages in antibody discovery to avoid downstream issues. We have previously developed a method (affinity-capture self-interaction nanoparticle spectroscopy, AC-SINS) that is capable of detecting weak antibody self-interactions using unusually dilute mAb solutions (tens of µg/ml).