The invention provides methods and materials for the conversion of cytosine to uracil. A nucleic acid, such a gDNA, is reacted with bisulfate, such as magnesium bisulfite, in the presence of a quaternary amine catalyst. Examples of suitable quaternary amine catalysts include but are not limited to quaternary ammonium compounds, quaternary alkyl ammonium salts, quaternary alkyl ammonium halides, quaternary methyl ammonium bromide, quaternary ammonium chloride, tetraethyl ammonium hydroxide, tetraethylammonium chloride, tetrabutyl ammonium chloride, tetrabutyl ammonium bromide. The invention also contemplates kits of premeasured ingredients for carrying out the methods of the invention either on an individual sample or on a plurality of samples.