Abstract: A cDNA clone is isolated encoding a bovine adrenal cytochrome P-450 specific for steroid 21-hydroxylation (P-450.sub.C21). This plasmid pC21a contains an insert of 520 base pairs. It hybridizes with mRNA encoding P-450.sub.C21. The peptide encoded by the insert is highly homologous to two peptides isolated from porcine P-450.sub.C21 and shows limited homology to the P-450 induced by phenobarbital in rat liver. This probe and its human equivalents can be used to screen in utero i.e. pre-natal as well as post-natal patients for adrenal hyperplasia since it reacts well with human DNA as shown. These probes can also be useful for an industrial fermentation process to produce cortisone in quantity.

Abstract: A micromethod for the determination of steroids in human body liquids, in particular blood, is disclosed. A small sample of the liquid is transferred to a sheet of absorbing material, e.g., filter paper. A disc of the impregnated paper, containing the dried sample, in eluted with an aqueous solvent, e.g., a buffer solution. Without separating the paper from the elute, the latter is extracted with an organic solvent. A steroid-containing residue is recovered from the organic extract and is subjected to a conventional radioimmunoassay. The method is particularly suited for the detection of disorders with elevated steroid levels such as congenital adrenal hyperplasia in newborn infants by determining the 17.alpha.-hydroxy-progesterone concentration in small blood samples.