Supervisor: Dr. Tran Thi My Hanh

Foremost, I would like to express my sincere gratitude to my supervisor Dr. Tran Thi My Hanh for her continual support of my thesis, for her patience, motivation, and immense knowledge. Her guidance helped me in all the time of research.Without her enthusiastic help and advices, this thesis would not be completed My special thanks also goes to all staffs of Biotechnology Laboratory for providing me a friendly and effective working environment. I would like to thank Ms. Ngoc, Ms. LanAnh who offered me all the instructions, chemicals and equipments needed. I am especially grateful to my fellow labmates Tung, Yen, Thuy, Thao who shared with me a lot of troubles during this thesis project. Without their cooperation and valuable helps, this thesis would not been progressed smoothly. Last but not the least, I would like to express my love, appreciation to my older brother for supporting and always encouraging me during my studies; to my parents for giving birth to me at the first place and supporting me spiritually throughout my life