Chemically defined cryopreservation media represent the most rigorously characterized class of formulations for the preservation of cells and tissues at ultralow temperatures. The term "chemically defined" denotes that all components of the medium are known, characterized, and present at defined concentrations, with no undefined biological extracts or variable raw materials. This classification distinguishes chemically defined media from related but less stringent categories: serum-free media exclude serum but may contain undefined protein hydrolysates; animal component-free (ACF) media exclude animal-derived components but may contain human-derived materials; and protein-free media exclude added proteins but may still contain undefined non-protein biological substances. The development of chemically defined cryopreservation media has been driven by the requirements of cell therapy manufacturing, where regulatory agencies demand reproducible, traceable, and low-risk ancillary materials.
Applications
Cell therapy manufacturing. This is a primary application, where GMP-grade, chemically defined formulations are required for regulatory compliance.
Stem cell research. Chemically defined media are used for the cryopreservation of human embryonic stem cells and induced pluripotent stem cells. CryoStem maintains human ES and iPS cell pluripotency and high recovery efficiency.
Biobanking. Biobanking benefits from the reproducible, traceable nature of chemically defined formulations.
Primary cell preservation. Media have been developed for the cryopreservation of human and animal primary cells.