Procedures for testing urine specimens dried on filter paper.

METHOD for collection of urine from infants onto squares of filter paper was described as part of a program for early detection of phenylketonuria (1). These urine papers have proved extremely versatile as an aid to testing urine for a number of substances that are excreted as a result of certain metabolic defects, all easily detectable by simple means. Phenylpyruvic acid, phenylalanine, and ohydroxyphenylacetic acid are excretory products characteristic of phenylketonuria (2, 3). A reducing sugar, galactose, is a significant finding in urine of patients with galactose disease (4). Sucrose has been reported in urine of several mentally retarded children (5)apparently the result of a defect in the enzyamtic system responsible for hydrolysis of the disaccharide. Chondroitin sulfuric acid has been found in urine of children with Hurler’s syndrome (gargoylism) (6, 7). METHODS