Picrolonic acid is primarily utilized in analytical chemistry as a reagent for the detection and quantification of metal ions, particularly calcium and magnesium. It forms characteristic crystalline complexes with these metals, which can be easily identified under a microscope, aiding in qualitative analysis. In biochemistry, it is employed to study enzyme inhibition and protein interactions due to its ability to bind with specific sites on proteins. Additionally, picrolonic acid is used in organic synthesis as a precipitating agent for isolating certain organic compounds, ensuring purity during chemical processes. Its application extends to pharmaceutical research, where it serves as a tool for investigating drug interactions and mechanisms at the molecular level.