DEPC

Diethyl pyrocarbonate, commonly abbreviated DEPC, is a chemical reagent used in molecular biology to inactivate ribonucleases (RNases) and thereby protect RNA in samples, solutions, and on surfaces. DEPC inactivates many RNases by covalently modifying key active-site residues, notably histidine, which prevents RNA degradation during handling and processing. The compound is highly reactive with water and many nucleophiles, and it degrades in aqueous solutions, so DEPC must be prepared and used with care in dry solvents and under appropriate safety conditions. Because of its reactivity, DEPC is typically stored in a dry environment and handled in a fume hood.

Applications and handling: In RNA work, DEPC is used to render water and buffers RNase-free. A common practice is to prepare a dilute DEPC solution in a dry solvent and add it to the target water or buffer, followed by incubation at an elevated temperature (commonly around 37°C) for several hours to inactivate RNases. The treated solutions are then autoclaved or otherwise subjected to conditions that decompose residual DEPC and its byproducts, after which the solutions are considered RNase-free. DEPC should not be used with materials that would be adversely modified, and care must be taken because DEPC can react with other biomolecules. Safety considerations include its toxicity and irritant properties; use appropriate personal protective equipment, work in a well-ventilated area, and dispose of waste according to local regulations.

Alternatives and limitations: While DEPC treatment remains a standard in some RNA protocols, many laboratories rely on RNase-free reagents, autoclavable water, and stringent aseptic techniques as alternatives or supplements. DEPC offers effective RNase inactivation but requires careful handling due to its hydrolysis in water and potential hazards.