Effective purification of human chorionic gonadotropin and its subunits from pregnant women urine

Human chorionic gonadotropin (hCG)، containing 30% sugar by molecular weight، is an important glycoprotein in pregnancy to keep the fetus. Nowadays، hCG has been used as the basis for the contraceptive vaccines. This study aimed to increase the hormone purity and shorten its purification time. For hCG purification، urine samples of 2-3 month pregnant women were collected and precipitated using sodium benzoat، acetic acid and acetone. The concentrated hCG was run on Concanavalin A column (Con-A) and eluted using D-Glucose and D-Mannose. To isolate the purified  and  subunits of hCG، the Con-A column was run on DEAE-Sepharose 4B column. The purity of hCG and its subunits was confirmed by SDS-PAGE and validated by ELISA and Immunoblotting. The concentrated urine sample and purified hCG sample were compared with the standard hCG control sample from Organon company، in terms of molecular weight and purity، using SDS-PAGE method and silver nitrate staining. Concentrated sample was identical to standard sample in number of additional bands، in which additional bands were removed after hCG purification. hCG hormone and its subunits were approved using the monoclonal antibodies against the α and β chains using ELISA and Western blot. According to the results of this study، hCG can be isolated from other parts of hCG and other glycoproteins using D-Glucose before D-Mannose.