Since the amino acid composition of hydrolysates of psoriatic scales might give some clues as to the pathology of the disease, it was decided to subject the hydrolysates to chromatographic analysis.The excellent method of column chromatography based on the use of ion exchange resins as developed by S. Moore and W. H. Stein1 was used in this work. The high degree of percision of the method, as well as the relatively short time required for a complete determination, recommend this procedure.
Preparation of the hydrolysate: The psoriatic scales were washed successively with ether and acetone in order to remove any lipid material which might be present. The washed and air-dried scales were kept in a vacuum dessicator over anhydrous calcium chloride.The acid hydrolysate was prepared by refluxing the tissue in 15 times its weight of 6 N HCl for a period of from 15 to
ZAHND H, CITRON M. The Amino Acid Composition of Exfoliative Tissue in Psoriasis. AMA Arch Derm. 1960;81(6):936–939. doi:10.1001/archderm.1960.03730060052009