Final answer:
The most common substance used to purify a membrane protein is detergents. They solubilize proteins by interacting with their hydrophobic regions and are categorized based on surfactant charge.
Step-by-step explanation:
The substance most commonly used to help purify a membrane protein is detergents. Detergents act as surfactants with the ability to solubilize membrane proteins by surrounding their hydrophobic regions and thereby enabling them to be suspended in aqueous solution without forming aggregates. These detergents are structured into various groups based on the electrical charge of the surfactants, which include nonionic, ionic, and zwitterionic detergents. Nonionic surfactants lower the surface tension of water, which helps emulsify oil and fat deposits and are less harsh on membrane proteins. This property makes them particularly useful for purifying membrane proteins in a lab setting. Other substances like enzymes, antibiotics, and salts have their specific uses, such as enzymes being used in household cleaning products and antibacterial purposes, but they are not primarily used for the purification of membrane proteins.