HENT buffer is provided as a 10X concentrate which is based on HEPES buffer saline with 0.5% v/v surfactant polysorbate 20 (Tween® 20). It can be diluted to 1X using deionized water. HENT is a running buffer used throughout a typical interaction experiment on Surface Plasmon Resonance (OpenSPR) instruments. Tween® 20 is a common additive which helps to reduce non? specific binding and sample loss, EDTA helps to chelate any heavy metal ions present in the buffer solution.