"Avidins are amongst the most widely used proteins in biotechnology, with applications encompassing molecular labelling, purification & detection, as well as uses in diagnostics, targeted drug delivery and nanotechnology, such as enantioselective catalysis by artificial catalysts. Avidins also serve as outstanding model systems for our understanding of biomolecular interactions, through their extremely high affinity for biotin (dissociation constant, Kd≈10−14–10−16 M).and biotinylated molecules. However, despite their importance in biotechnology, only two avidins have found widespread and routine use amongst the scientific community: chicken avidin and bacterial streptavidin. DIVA aims to exploit the recent identification of novel avidins in DNA sequence databases to generate novel variants of these proteins. DIVA will also use protein engineering to provide further genetic diversity, such as defined asymmetric tetramers of avidins consisting of different subunits. The overall aim is to expand the range of avidins available to biotechnologists and to increase their use and potential applications."