Prior to protein purification experiments, it is necessary to clarify the protein tag, expression host and purification protocol. Prepare binding, washing, elution and other buffers, filter and sterilize them, and prepare additives such as protease inhibitors. Pre-cool instruments and consumables, and prepare chromatography columns, centrifuge tubes, quantification and electrophoresis reagents. Clean the operating platform, ensure a low-temperature environment and safety protection, and plan the procedures for sample lysis and clarification.