Our NIH-funded project (1 R15GM152969-01) focuses on synthesizing and characterizing fluorescent probes operating in the red to near-infrared region to measure pH levels within organelles. The current synthesis involves multiple steps, with silica gel chromatography causing delays and inefficiencies. The proposal suggests acquiring a preparative high-pressure liquid chromatography (HPLC) system to improve purification at each step, addressing the limitations of traditional silica gel column chromatography. The decision is driven by the complexity of the probes and the need for enhanced resolution in separating closely related compounds. The shift to preparative HPLC is expected to streamline the synthesis process and improve the overall efficiency of the project.