Potassium acetate (CH3COOK) is the potassium salt of acetic acid. Potassium acetate can be used as a deicer to remove ice and prevent its formation, as a food additive as a preservative and acidity regulator, as extinguishing agent used in Class K fire extinguishers because of its ability to cool and form a crust over burning oils, as a catalyst in the production of polyurethanes. In medicine, potassium acetate is used as part of replacement protocols in the treatment of diabetic ketoacidosis because of its ability to break down into bicarbonate and help neutralize the acidotic state. In molecular biology, potassium acetate is used to precipitate dodecyl sulfate (DS) and DS-bound proteins, allowing the removal of proteins from DNA. It is also used as a salt for the ethanol precipitation of DNA.