Background Follicle stimulating hormone (FSH)- a hetrodimeric glycoprotein- is secreted by pituitary gland. This hormone stimulates growth and maturation of the follicles in females and sperms in male. Up to now, glycoprotein hormones such as FSH have produced in different cell lines. Among of the mammalian expression systems, the Chinese hamster ovary cells (CHO) have taken into consideration ...