Description General description Estrone, a precursor of estradiol, is monitored in serum or plasma by LC-MS/MS or GC/MS to assess and diagnose developmental abnormalities, enzyme inactivity or deficiency, polycystic ovary syndrome (PCOS), or hormone replacement therapy in women. This 13C-labeled internal standard of estrone is suitable for quantitation of estrone in serum or plasma by LC-MS/MS or GC/MS for clinical testing and can eliminate potential issues of isotopic exchange as well as minimize separation of later-eluting analytes from a higher substituted deuterium-labeled internal standard. Legal Information CERILLIANT is a registered trademark of Cerilliant Corporation