Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) refers to a widely used laboratory technique used for separating and analyzing proteins. It is a variation of gel electrophoresis that involves the use of Sodium Dodecyl Sulfate (SDS), a strong anionic detergent, along with polyacrylamide gel.
The process starts by denaturing the proteins with SDS, which helps in the uniform binding of SDS molecules to the protein molecules, resulting in the formation of a negative charge on the proteins. This binding disrupts the native protein conformation, as SDS binds to the hydrophobic regions of proteins, causing them to unfold into linear chains. The mixture of SDS-denatured proteins is then loaded onto a polyacrylamide gel, which acts as a molecular sieve.
During the electrophoresis step, an electric current is applied to the gel system. The negatively charged proteins migrate through the gel towards the positive electrode, with smaller proteins moving faster and migrating further, while larger proteins move slower and remain closer to the loading point. This separation is facilitated by the polyacrylamide matrix which acts as a sieve, allowing the separation based on size. As a result, the proteins are separated according to their molecular weight and form distinct bands or bands of similar-sized proteins on the gel.
SDS-PAGE is widely utilized in various research areas, such as biochemistry, molecular biology, and biotechnology, to investigate protein composition, purity, molecular weight, and protein expression levels. This technique is crucial for protein analysis, purification, and characterization, enabling researchers to gain insights into protein structure, function, and other biochemical properties.
