DEPC-Treated Water

DEPC is a non-specific inhibitor of Ribonucleases (RNases). To reduce degradation of RNA in experiments, water is treated with DEPC. A concentration of 0.1 % DEPC is used to reduce RNase contamination in laboratory procedures. DEPC modifies enzymes containing -NH, -SH, or -OH groups in their active sites. DEPC particularly reacts with Cys, His, Lys, Ser and Tyr residues of proteins. DEPC-Treated Water is prepared by adding DEPC to water and autoclaving the solution. Autoclaving inactivates DEPC by causing hydrolysis of DEPC and release of by-products ethanol and carbon-dioxide. DEPC has a half-life of approximately 30 min in water. DEPC-Treated Water (0.1%) can be used with buffers such as PBS and MOPS but cannot be used with the buffers Tris and HEPES. Tris and HEPES make DEPC unavailable to inactivate RNase. DEPC-treated water should not be added to aqueous solutions of ammonia as it will result in the formation of urethane, a possible carcinogen.