Elecsys estradiol 3 kit

For 17β‐estradiol quantification, SUM149PT cells were treated for 48 h with 100 nm calcitriol and then harvested, washed three times in PBS 1×, and then lysed and sonicated. After clarification, total proteins of the lysate were measured by Bio‐Rad Protein Assay (Bio‐Rad Laboratories) to allow sample normalization. One hundred microliter of cell lysate was utilized for 17β‐estradiol quantification by the eletrochemiluminescence immunoassay (ECLIA) Elecsys Estradiol III kit–Roche Canada on COBAS analyzer, according to the manufacturer's instructions. The minimum detectable dose of 17β‐estradiol was 5 pg·mL⁻¹. The measurements were run in triplicates and were preceded by blank.

For the determination of the hormonal profile, participants with overnight fast were arranged in sitting posture for 30 min before sampling, and then blood samples were drawn from the antecubital veins between 8 and 10 am. Serum samples were analyzed for follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), total testosterone (T), estradiol (E₂), and thyroid-stimulating hormone (TSH). When abnormal values appeared, a second sample of the blood was obtained for the re-assessment. The hormonal levels were investigated using the Cobas 6,000 analyzer series (Roche Diagnostics GmbH, Mannheim, Germany) in the laboratory department of the hospital. Among these hormones detected, serum estradiol levels were measured using Elecsys estradiol III kit (Roche Diagnostics Ltd., Shanghai, China). The lower and upper detection limits for estradiol were 28.0 and 156.0 pmol/L, respectively. In addition, the intra-assay coefficient of variation was below 10%, and inter-assay coefficient of variation was below 15%.

A chemiluminescence immunoassay was applied in order to quantify E2 concentrations in serum samples using the Elecsys Estradiol III kit (Roche Italia S.p.A., Monza, Italy). The assay was carried out according to manufacturer instructions. The detection limit of the assay was equal to 5 pg/mL.