Conjugated oestrogen during the menstrual cycle measured by a direct radioimmunoassay with an antiserum prepared against oestradiol-17-glucosiduronate-[C-6]-BSA conjugate

Abstract
Early morning and 24 h urine samples and serum were collected daily throughout the menstrual cycle in women. Urinary oestradiol-17-glucosiduronate (E2-17-G) was measured with a direct radioimmunoassay whose antiserum had been prepared against E2-17-G-[C-6]-bovine serum albumin conjugate and was very specific. On the average, E2-17-G in early morning and 24 h urine samples showed a prominent peak one day before the peak of urinary LH. The time relationship between these urinary E2-17-G and serum E2 levels and peaks was also investigated.