One of the most important parts of Abcore’s nanobody discovery platform is our proprietary phage display technology. We have continued to refine our protocols over the years, optimizing our phage display for nanobody discovery.
Our phage display starts with either an immunized or naïve nanobody library. We first use panning to enrich the library for nanobodies that bind to the target. We often use pre-panning steps to address the cross-reactivity goals of the project. We can pan to remove any binders to closely related isoforms or use a parental or knock-out cell line for cell-based projects. Once we have performed rounds of screening, and we see good enrichment, we move to selection.
Abcore’s proprietary OPIS technology allows us to screen the enriched phage pools for positive binders in the absence of phage. This removes the possibility of non-specific phage binders (phage is known for being very sticky) and only detect nanobodies that bind to the target of interest.
Abcore actually confirms binding to the target twice before even sequencing the clones. We call this OPIS 1 and OPIS 2. After OPIS 2, we sequence all positive clones from the first screening plate(s) and we then dereplicate this list to deliver a list of positive, unique nanobody binders.