What is the primary advantage of using sodium dodecyl sulfate in SDS-PAGE?

The primary advantage of using sodium dodecyl sulfate (SDS) in SDS-PAGE (SDS-polyacrylamide gel electrophoresis) is that it effectively eliminates the influence of protein structure and charge. SDS is an anionic detergent that denatures proteins by binding to their polypeptide chains, which causes the proteins to unfold and acquire a uniform negative charge proportional to their length. This process ensures that the resulting separation of proteins during electrophoresis is based primarily on their size rather than their intrinsic charge or conformation.

By stripping away the complex three-dimensional structures that proteins may exhibit, SDS-PAGE allows for a more straightforward comparison of proteins based on molecular weight. This uniformity enables researchers to accurately assess protein sizes when visualizing the gel results, making it a crucial step in protein analysis and characterization.

While other options may hold relevance in their own contexts—such as improving resolution or allowing for faster separation of DNA—these do not directly relate to the fundamental function of SDS in protein analysis.