Affimer screening facility
Synthetic libraries – Synthetic library, replaces animal immunisation and allows screening of toxic and non-immunogenic targets in vitro. Affimers have been selected against more than 500 targets including toxins, SH2 domains, human sumo isoforms, ubiquitin linkages and small molecules
Development time – The in vitro screening of Affimer proteins including phage ELISA and sequencing of positive clones normally only takes 3-4 weeks
Specificity –around $800 million per year is estimated to be wasted on poorly validated antibodies with low specificity. The level of Affimer specificity and the technique used for Affimer isolation is ideal for isolating reagents with high specificity (see publications list).
Ease of production in E. coli – Affimer proteins can be reproducibly produced in the most cost- and time-saving expression system – E. coli - (up to 200 mg/L in a shaker flask).
Small size – Small binding reagents are of particular interest as imaging reagents. Affimer proteins (ca. 12 kDa) can readily penetrate tissues and access epitopes in densely packed subcellular structures of cells more readily than antibodies. They also position a fluorophore label in closer proximity to the target of interest and generate an increased spatial resolution in super-resolution microscopy. They also have an improved packing density on solid surfaces in ELISA or biosensors leading to improved sensitivities.
Stability – Affimer proteins are stable with Tm up to 100°C and across a broad pH range. This offers major storage and shipping advantages.
- Expression in cells – conventional antibody-based research reagents cannot be used for in vivo studies. Affimer proteins can be used to study intracellular protein-protein interactions and opens new research opportunities.
- Ease of crystallisation – Affimer proteins crystallise readily enabling access to structural interaction information for design of small molecules for potential therapeutic applications.
- Simple protein, easy to engineer – Affimer proteins do not contain disulfides and can be easily manipulated for the generation of a) fusion proteins, bbi- and polymeric Affimer reagents, or c) labelling with biotin, proteins including enzymes or fluorophores.
- Non-immunogenic – Our industrial partner Avacta has shown that the Affimer scaffold has low immunogenicity using a peripheral blood mononuclear cell test.