It does so by the covalent modification of histidine (most strongly), lysine, cysteine, and tyrosine residues.

Higher concentrations of DEPC are capable of deactivating larger amounts of RNase, but remaining traces or byproducts may inhibit further biochemical reactions such as in vitro transcription.

DEPC is unstable in water and susceptible to hydrolysis to carbon dioxide and ethanol, especially in the presence of a nucleophile.

DEPC derivatization of histidines is also used to study the importance of histidyl residues in enzymes.

Modification of histidine by DEPC results in carbethoxylated derivates at the N-omega-2 nitrogen of the imidazole ring.