Preliminary identification of plasma steroids in the plaice, Pleuronectes platessa L

Fresh plasma (750 ml) was collected from mature female plaice caught in the North Sea during March 1971. Cortisol and testosterone were identified by paper chromatography, by the formation of nonsequential derivatives, and by the measurement of specific activities of derivatives following chromatography. Progesterone was identified on the basis of the formation of a single derivative. Oestradiol-17 β and oestrone were each identified by paper chromatography, by colour reactions, and by the formation of four sequential derivatives.