SDS-PAGE（Sodium Dodecyl Sulfate - Polyacrylamid Gel Electrophoresis）

SDS is a common ingredient in detergents Other names for SDS include laurel sulfate and sodium laurel sulfate As a detergent SDS destroys protein secondary, tertiary and quaternary structure This makes proteins rod shaped SDS also sticks to proteins in a ratio of approximately 1.4 g of SDS for each gram of protein Negative charge on the sulfate groups of SDS mask any charge on the protein

SDS Sodium Dodecyl Sulfate Because it is amphipathic, SDS is a potent detergent SDS may also be called sodium lauryl sulfate and is a common ingredient of shampoos laundry detergent and other cleaning products SDS and Proteins

SDS nonpolar chains arrange themselves on proteins and destroy secondary tertiary and quarternary structrure Thus shape is no longer an issue as the protein SDS complex becomes rod shaped

In aqueous solutions, SDS polarizes releasing Na+ and retaining a negative charge on the sulfate head So much SDS binds to proteins that the negative charge on the SDS drowns out any net charge on protein side chains In the presence of SDS all proteins have uniform shape and charge per unit length

Polyacrylamide Gels Polyacrilamide is a polymer made of acrylamide (C 3 H 5 NO) and bis-acrilamide (N,N’-methylene-bis-acrylamide C 7 H 10 N 2 O 2 )