Laemmli's (SDS-Sample) Buffer is widely used in molecular biology and biochemistry for protein analysis, particularly in SDS-PAGE (Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis). It serves as a sample buffer to prepare protein samples for separation based on molecular weight. The buffer contains SDS, which denatures proteins by breaking non-covalent bonds and imparting a uniform negative charge, ensuring proteins migrate through the gel according to size. It also includes glycerol to increase sample density, allowing it to settle into gel wells, and bromophenol blue as a tracking dye to monitor electrophoresis progress. Additionally, the buffer often contains a reducing agent like β-mercaptoethanol or DTT to break disulfide bonds, further ensuring complete protein denaturation. This makes it essential for accurate protein characterization, immunoblotting, and other downstream applications.