6. Conclusion

Conservation with preservation of the functionality of biological cells, tissues or organs is a fast-growing reality today.

The main effective methods for long-term preservation are :

• FREEZING ;

• freeze-drying ;

• convective drying.

Freezing is used for animal, plant and microbial cells. Techniques based on dehydration are more suitable for microbial cells. For each type of cell, tissue or organ, the development of a specific protocol is generally necessary, since each biological system is characterized by a specific geometry, membrane permeability, mechanical and physiological resistance.

The number of future applications should continue to grow as fundamental knowledge of the biological and...