Affimer proteins are versatile and renewable affinity reagents

Christian Tiede, Robert Bedford, Sophie J Heseltine, Gina Smith, Imeshi Wijetunga, Rebecca Ross, Danah AlQallaf, Ashley PE Roberts, Alexander Balls, Alistair Curd, Ruth E Hughes, Heather Martin, Sarah R Needham, Laura C Zanetti-Domingues, Yashar Sadigh, Thomas P Peacock, Anna A Tang, Naomi Gibson, Hannah Kyle, Geoffrey W Platt, Nicola Ingram, Thomas Taylor, Louise P Coletta, Iain Manfield, Margaret Knowles, Sandra Bell, Filomena Esteves, Azhar Maqbool, Raj K Prasad, Mark Drinkhill, Robin S Bon, Vikesh Patel, Sarah A Goodchild, Marisa Martin-Fernandez, Ray J Owens, Joanne E Nettleship, Michael E Webb, Michael Harrison, Jonathan D Lippiat, Sreenivasan Ponnambalam, Michelle Peckham, Alastair Smith, Paul Ko Ferrigno, Matt Johnson, Michael J McPherson, Darren Charles Tomlinson

Molecular recognition reagents are key tools for understanding biological processes and are used universally by scientists to study protein expression, localisation and interactions. Antibodies remain the most widely used of such reagents and many show excellent performance, although some are poorly characterised or have stability or batch variability issues, supporting the use of alternative binding proteins as complementary reagents for many applications. Here we report on the use of Affimer proteins as research reagents. We selected 12 diverse molecular targets for Affimer selection to exemplify their use in common molecular and cellular applications including the (a) selection against various target molecules; (b) modulation of protein function in vitro and in vivo; (c) labelling of tumour antigens in mouse models; and (d) use in affinity fluorescence and super-resolution microscopy. This work shows that Affimer proteins, as is the case for other alternative binding scaffolds, represent complementary affinity reagents to antibodies for various molecular and cell biology applications.