Estradiol(E2) CLIA kit (Chemiluminescence Immunoassay) is an in vitro diagnostic quantitative test kit. E2 plays an important role in the menstrual cycle, supporting pregnancy and maintaining reproductive health. Estradiol plays an essential role throughout the human menstrual cycle. Elevated estradiol levels in females may also result from primary or secondary ovarian hyperfunction. Decreased estradiol levels in females may result from either lack of ovarian synthesis (primary ovarian hypofunction and menopause) or a lesion in the hypothalamus-pituitary axis (secondary ovarian hypofunction).