An enzyme-linked immunosorbent assay (ELISA) for plasma progesterone: immobilised antigen approach.

A single extraction ELISA for plasma progesterone is described using the fixed antigen approach. Progesterone is covalently coupled to bovine thyroglobulin and adsorbed onto a 96-well microtitre plate in guanidine hydrochloride. The assay, performed on an automatic ELISA processor, follows an established methodology used for other steroid hormones analysed in this laboratory with concomitant advantages in assay standardisation, cost structure and result throughput. A comparison with an established RIA shows the assay to be rapid, of similar specificity and accuracy with a sensitivity of less than 0.5 nmol/l and is suitable for use in a routine endocrine laboratory for determination of luteal function.