SDS-PAGE

SDS-PAGE (Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis) is a laboratory technique used to separate proteins based on their size. Proteins are first treated with a detergent called SDS, which unfolds them into linear shapes and gives all proteins a uniform negative charge. When the sample is loaded into a gel and an electric current is applied, proteins move through the gel matrix. Smaller proteins travel faster and farther, enabling scientists to estimate their sizes by comparing their positions to known standards. This method helps analyze protein composition and purity in research and diagnostics.