This product is a serum-free medium for BHK-21 cells, a chemically defined medium specifically designed for high-density culture of hamster kidney cells (BHK-21) and production of recombinant proteins/viral vectors. Its core formulation precisely mimics the unique metabolic characteristics of BHK-21 cells. By optimizing amino acid profiles, energy substrates, and key surface factors, it significantly enhances cell adhesion/suspension adaptability and target product expression efficiency. Simultaneously, it completely eliminates batch-to-batch variability, exogenous factor risks, and downstream purification interference associated with serum introduction.