Antibodies or nanobodies can be used to immobilize proteins on various surfaces, such as microtiter plates, beads or biosensors. Protein-protein interactions and affinity (k_on/k_off and K_D values) can be measured with ligand capture-based assay setups, e.g. by surface plasmon resonance (SPR, Biacore^TM/GE Healthcare), biolayer interferometry (BLI, FortéBio/Pall) or the switchSENSE® technology (Dynamic Biosensors). As a prerequisite for these assays, the affinity of the antibody or Nanobody to the capture ligand has to be high enough to assure ligand binding during the time of the measurement.

ChromoTek’s anti-GFP Nanobody has an extremely high affinity to GFP, with a K_D value of approx. 1 pM, as determined by switchSENSE. Note that the other Nanobodies from ChromoTek like the GST, MBP VHHs do have single digit nanomolar K_D values, which also allow for high affinity binding in before mentioned applications. Therefore, it is a perfect tool for capturing GFP-tagged proteins for protein-protein interaction studies and affinity determination. Furthermore, its high stability allows regeneration and reuse of the biosensor for multiple measurements.