Progesterone

The DRG:HYBRiD-XL Progesterone is an enzyme immunoassay for the quantitative in vitro diagnostic measurement of progesterone in serum and plasma.Only for use with the DRG:HYBRiD-XL Analyzer.Progesterone (pregn-4-ene-3, 20-dione) is a C21 steroid hormone containing a keto-group (at C-3) and a double bond between C-4 and C-5 (Δ4). Progesterone circulates in blood mainly bound to Corticosteroid Binding Globulin (CBG), Sex Hormone Binding Globulin (SHBG) and Albumin. Only 2-10% of the total concentration circulates as free hormone (1). This steroid hormone is a female sex hormone which, in conjunction with estrogens, regulates the accessory organs during the menstrual cycle and it is particularly important in preparing the endometrium for the implantation of the blastocyte and in maintaining pregnancy. In non-pregnant women progesterone is mainly secreted by the corpus luteum whereas in pregnancy the placenta becomes the major source (2). Minor sources are the adrenal cortex for both sexes and the testes for males. Adult males have levels similar to those in women during the follicular phase of the menstrual cycle. Blood progesterone concentrations vary widely according to the phases of menstrual cycle; they are 0.2-1.5 ng/mL in the follicular phase and around 1.7-27 ng/mL in the luteal phase (3). The maximal levels are achieved 4-7 days after ovulation and remain elevated for 4-6 additional days prior to falling to the preovulatory levels 24 hours before the onset of menstruation. Since the rise and fall of progesterone parallel the activity of ovarian follicle and corpus luteum, measurements of plasma progesterone are clinically used to confirm ovulation and normal function of the corpus luteum in non-pregnant women. Progesterone levels are relatively low in children and postmenopausal women (3). Progesterone concentration can vary not only from subject to subject but also in the same person from day to day or even fromhour to hour (4,5). Consequently, in gynecological disorders or abnormal pregnancies serial measurements rather than single ones are recommended for a proper interpretation of results. The DRG:HYBRiD-XL Progesterone Kit is a solid phase enzyme-linked immunosorbent assay (ELISA) based on the principle of competitive binding. The antibody coated wells (ACW) of the reagent cartridges are coated with a polyclonal antibody directed towards a unique antigenic site of the progesterone molecule. Endogenous progesterone of a patient sample competes with a progesterone-horseradish peroxidase conjugate for binding to the coated antibody. After incubation the unbound conjugate is washed off. The amount of bound peroxidase conjugate is inversely proportional to the concentration of progesterone in the sample. Having added the substrate solution, the intensity of colour developed is inversely proportional to the concentration of progesterone in the patient sample.