Galactosemia TGAL

The enzymatic reaction of the NEONATAL Total-Galactose Screening Assay is carried out in two stages. In the first stage, two enzymes—alkaline phosphatase and galactose dehydrogenase—convert total galactose (Galactose-1-phosphate and free galactose) in the newborn sample into products, such as NADH. In the second stage, the presence of NADH is quantified using colorimetry with tetrazolium salt. The absorbance intensity measured is directly proportional to the total galactose concentration in the sample.