Phase separation, particularly liquid-liquid phase separation (LLPS), has emerged as a powerful tool in biological research, offering unique advantages for visualizing and analyzing biomolecular interactions. This review highlights recent advances in leveraging LLPS to develop experimental techniques for studying protein-protein interactions (PPIs), protein-RNA interactions, and enzyme activity. The integration of LLPS with advanced techniques has expanded its applications, offering new possibilities for unraveling the complexities of cellular function and disease mechanisms. Looking forward, the development of more versatile, sensitive, and targeted LLPS-based methods is poised to transform molecular biology, providing deeper insights into cellular dynamics and facilitating therapeutic advancements.