Cryopreservation is a method to store cells at very low temperatures. By using special chemicals called cryoprotective agents, cells can survive freezing and thawing. The speed at which cells are cooled and thawed also affects their survival. Different types of cells require specific conditions for successful cryopreservation. For example, oocytes and pancreatic islets do better with fast cooling, while hepatocytes and stem cells prefer slow cooling. Adding glucose and antioxidants before freezing, encapsulating cells, and choosing cells of the right age and function can improve the process. Testing cell viability and function after thawing is crucial for assessing the quality of preserved cells.