Heterogeneity of human chorionic gonadotropin in various biological fluids as revealed by chromatofocusing

This study demonstrates that chromatofocusing is powerful in analyzing multiple forms of hCG from biological fluids. For analyzing hCG from biological fluids, it is necessary to perform chromatofocusing, in the range of pH 6.2-3.0 and pH 9.0-6.0. By chromatofocusing, highly purified hCG (CR121) was found to be acidic, in the range of pI 4.22-3.8, and hCG beta was more acidic, in the range of pI 4.0-3.2. Moreover, hCG from the first trimester pregnancy, hydatidiform mole or choriocarcinoma was also mainly acidic. Therefore, chromatofocusing in the range of 6.2-3.0 was suitable for analyzing purified hCG, hCG beta, and urinary hCG from the first trimester pregnancy, hydatidiform mole and choriocarcinoma. On the other hand, because hCG in the third trimester pregnancy and the toxemia of pregnancy were mainly alkaline, the chromatofocusing system in the range of pH 9.0-6.0 was suitable for analyzing hCG from the third trimester pregnancy and the toxemia of pregnancy.