What lab procedure detects the identity and purity of a specific protein?

SDS-PAGE, or Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis, is a powerful technique used to separate proteins based on their molecular weight. This procedure involves denaturing the proteins and applying them to a polyacrylamide gel, where an electric current is used to drive the proteins through the gel matrix. Smaller proteins migrate faster and thus move further down the gel compared to larger ones.

By visualizing the separated proteins, usually through staining techniques, researchers can assess both the identity and purity of a specific protein. The results allow for the determination of the presence of the target protein, as well as checking for any impurities, such as other proteins or degradation products, indicated by additional bands in the gel. The clear separation of bands helps in confirming the molecular weight of the protein of interest, providing further insight into its identity.

In contrast, the other techniques mentioned serve different purposes. ELISA is primarily used for quantifying the concentration of a specific protein in a sample through an antigen-antibody interaction, without providing details about purity or molecular weight. Western blotting combines separation via SDS-PAGE with specific detection of proteins using antibodies, but this method is more focused on confirming the presence of a