Tris-HEPES Native Running Buffer is primarily used in gel electrophoresis for the separation and analysis of proteins under native conditions. It helps maintain the natural conformation and biological activity of proteins during the process, making it ideal for studying protein-protein interactions, enzyme activity, and protein complexes. The buffer ensures stable pH and ionic strength, which are crucial for accurate and reproducible results. It is commonly employed in research laboratories for applications such as western blotting, native PAGE, and other protein analysis techniques where preserving protein structure is essential.