MEASUREMENT OF PROGESTERONE IN HUMAN PLASMA

A rapid protein-binding technique is described for routine plasma progesterone measurements. Chick plasma is the source of binding-protein and ³H-progesterone is the radioligand. Accuracy is ensured by including a recovery determination with each specimen. In fifteen normal female volunteers, low plasma progesterone values-0.65 ng/ml ± 0.82 (SD)-were recorded during the follicular phase of the menstrual cycles, rising 10-14 days before menstruation to peak levels of 9–17 ng/ml during the luteal phase and then falling abruptly towards the end of the cycle.