Laemmli's Buffer with Pyronin Y non-reducing is primarily used in molecular biology and biochemistry for protein analysis. It is commonly employed in SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) to prepare protein samples for separation. The inclusion of Pyronin Y, a tracking dye, allows researchers to monitor the progress of electrophoresis visually. This buffer ensures proteins remain in their native, non-reduced state, making it suitable for studying protein complexes, interactions, or conformations without disrupting disulfide bonds. It is particularly useful in applications where maintaining the structural integrity of proteins is critical.