Tris have been useful as buffers in a wide variety of biological systems. It has been used as a starting material for polymers, oxazolones (with carboxylic acids) and oxazolidines (with aldehydes). It does not precipitate calcium salts and is of value in maintaining solubility of manganese salts. It can be used for the direct standardization of a strong acid solution; the equivalence point can be determined either potentiometric ally or by use of a suitable indicator such as 3-(4-Dimethylamino-1-naphthylazo)-4-methoxybenzenesulfonic acid. It is RNAse and DNAse-free. Tris is relatively non-hygroscopic; but, if needed, it can be dried at 100°C for up to 4 hours to remove any water. Tris is used in pH control in vitro and in vivo for body fluids and in buffering systems for electrophoresis applications. Tris is used in assays used to characterize the activity and kinetics of the enzymes that catalyze SUMOylation of Small ubiquitin-like proteins (SUMO) and SUMO-dependent protein-protein interactions.