Phenylketonuria screening with a fluorometric microplate assay.

A fluorometric assay in microtitre plates for the screening of phenylketonuria was evaluated and adapted to a neonatal screening programme. Using this assay, it is possible to determine quantitatively the phenylalanine concentration in dried blood spots on filter paper. The test exhibited a linear calibration curve with a good slope as well as sufficient precision and accuracy in the statistical analysis.

Colorimetric determination of galactose and galactose-1-phosphate from dried blood.

A colorimetric microassay for the simultaneous quantitative determination of galactose (Gal) and galactose-1-phosphate (Gal-1-P) in dried blood spots is described. An enzymatic reaction involving alkaline phosphatase (EC 3.1.