Tris-HCl is a solution containing a tris base mixed with hydrocholoric acid. Tris-HCl is used to buffer solutions from large changes in pH level. It is designed to keep solutions within a pH range of 7.0 to 9.0.
Tris base does not create a buffer by itself and must be mixed with a titration of hydrochloric acid to achieve buffering potential. As a buffer, Tris-HCl is used in DNA and RNA extractions and for antigen retrieval in immunochemistry. It has also been used with coelomic fluid to store unfertilized eggs of fish such as rainbow trout. Tris-HCl is also utilized in smooth muscle research to inhibit motor responses and motor nerve stimulation.