Evaluation of a simple thin-layer chromatographic screening test for amino acid abnormalities A thin-layer chromatographic test* .' was used to screen blood specimens from infants and children for elevations of amino acids to determine its sensitivity for detection of known abnormalities and to note the frequency of positive findings among previously untested patients . The procedure permits chromatographic separation of amino acids in plasma on precoated cellulose plates without deproteinization .
Methods
One-hundred sixty-two specimens were obtained from premature infants in Cincinnati General Hospital at weekly intervals from birth to discharge. Random samples were collected from 196 patients in Cincinnati Children's Hospital . Other subjects included infants suspected of phenylketonuria identified in the Ohio State screening program, patients being treated for phenylketonuria, patients with galactosemia, treated and untreated, and patients previously shown to have histidinemia and hyperglycinemia .
Basic equipment included glass plates, io x 2o cm, precoated with cellulose, 2 Ul capillaries and holder for application of samples ; solvents : it-butanol-acetone (1 :i) and acetic acid-water (1 :2) ; reagent : 0.4 M ninhydrin in butanol-acetone ; and a standard solution of amino acids in concentrations corresponding to the upper limit of normal for 5-day-old infants . NOTES 0 Arginine o .6 2 .2 Lysine 3 .9 4 .5 Histidine 2 .3 8 .5
NOTES compared to specific tests for amino acids in that a generalized aminoacidemia can be readily detected .