Recombinant protein lyophilization is a low-temperature vacuum drying process designed to preserve protein bioactivity for long-term storage. First, aliquot purified recombinant proteins and add lyoprotectants such as mannitol and trehalose. After thorough mixing, pre-freeze the samples below -40 °C to fully convert water in the solution into ice crystals. Transfer the frozen samples to the vacuum chamber of a lyophilizer, where ice crystals sublimate under low temperature and low pressure to remove free water, followed by secondary drying to desorb bound water.