AVIDITY
Numerous and varied formats of immobilized streptavidin and related proteins are available, but predicting which product is most apt for a given application is complicated by the fact that there are numerous technical considerations and no universal reporting standards for describing the binding capacity of the beads. To overcome these challenges, we developed a colorimetric competitive displacement assay, the streptAVIdin binDing capacITY (AVIDITY) assay, a fast, easy, and inexpensive absorbance-based method to measure the binding capacity of streptavidin beads, which can be used to compare different products and evaluate variation among many of the same product. The AVIDITY assay benefits users across disciplines to make informed decisions regarding the most apt streptavidin bead products for their own experiments.