Superoxide is known to denature enzymes, oxidize lipids, and fragment DNA. They irreversibly denature or destroy many proteins, making them extremely versatile disinfectants. Prior to electrophoresis, protein samples are often boiled to denature the proteins present. SDS is a strong detergent agent used to denature native proteins to unfolded, individual polypeptides. This process does not denature proteins, because the detergents only affect lipids and lipid derivatives. Scleroproteins tend not to denature as easily as globular proteins. The ions bond electrostatically with negative sites on bacterial cell walls and denature proteins. Higher temperatures will denature the proteins, resulting in slower or even no curdling. Eggs consist of proteins which denature when heat is applied. These advantages come at the cost of unwanted substrate interactions which can denature membrane proteins. Proteins can denature in environmental conditions the protein is not made for. When proteins denature, they are not in a stable state. The RIPA buffer gives low background but can denature kinases. Aniline was used to denature colza oil in the 1980s. Some viruses, when exposed to a low pH, will denature spontaneously.