Diethyl pyrocarbonate

Diethyl pyrocarbonate

Names
IUPAC name Diethyl dicarbonate
Other names Diethylpyrocarbonate Diethyl oxydiformate Ethoxyformic anhydride Pyrocarbonic acid diethyl ester DEPC
Identifiers
CAS Number	1609-47-8 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:59051 Y
ChemSpider	2943 Y
ECHA InfoCard	100.015.039
KEGG	C11592 Y
MeSH	Diethylpyrocarbonate
PubChem CID	3051
InChI InChI=1S/C6H10O5/c1-3-9-5(7)11-6(8)10-4-2/h3-4H2,1-2H3 Y Key: FFYPMLJYZAEMQB-UHFFFAOYSA-N Y InChI=1/C6H10O5/c1-3-9-5(7)11-6(8)10-4-2/h3-4H2,1-2H3 Key: FFYPMLJYZAEMQB-UHFFFAOYAU
SMILES O=C(OCC)OC(=O)OCC
Properties
Chemical formula	C6H10O5
Molar mass	162.14 g·mol−1
Appearance	Clear, colorless liquid
Density	1.101 g/mL at 25 °C 1.121 g/mL at 20 °C
Boiling point	93 to 94 °C (199 to 201 °F; 366 to 367 K) at 24 hPa
Hazards
Main hazards	Harmful
R-phrases (outdated)	R22 R36/37/38
Flash point	69 °C (156 °F; 342 K) closed cup
Lethal dose or concentration (LD, LC):
LD50 (median dose)	Oral - rat - 850 mg/kg
Related compounds
Related compounds	Di-tert-butyl dicarbonate Dimethyl dicarbonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Diethyl pyrocarbonate (DEPC), also called diethyl dicarbonate (IUPAC name), is used in the laboratory to inactivate RNase enzymes in water and on laboratory utensils. It does so by the covalent modification of histidine (most strongly), lysine, cysteine, and tyrosine residues.

DEPC-treated (and therefore RNase-free) water is used in handling of RNA in the laboratory to reduce the risk of RNA being degraded by RNases.

Water is usually treated with 0.1% v/v DEPC for at least 2 hours at 37 °C and then (at least 15 min) to inactivate traces of DEPC. Inactivation of DEPC in this manner yields CO₂ and ethanol. 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 translation. Furthermore, chemical modification of RNA such as carboxymethylation is possible when traces of DEPC or its byproducts are present, resulting in impaired recovery of intact RNA even after buffer exchange (after precipitation).

DEPC is unstable in water and susceptible to hydrolysis to carbon dioxide and ethanol, especially in the presence of a nucleophile. For this reason, DEPC cannot be used with Tris or HEPES buffers. In contrast, it can be used with phosphate-buffered saline or MOPS. A handy rule is that enzymes or chemicals which have active -O:, -N: or -S: cannot be treated with DEPC to become RNase-free, as DEPC reacts with these species. Furthermore, DEPC degradation products can inhibit in vitro transcription.

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. DEPC modification of histidines can be reversed by treatment with 0.5 M hydroxylamine at neutral pH.