Quantitation of Phenylalanine in Dried Blood Spot Using Liquid Chromatography Tandem Mass Spectrometry for Monitoring of Patients with Phenylketonuria (PKU).
Newborn screening for phenylketonuria (PKU) is performed by analysis of phenylalanine in dried blood spot (DBS). Once diagnosed by a definitive method, a patient's dietary control is performed by repeated analysis of phenylalanine in venous blood or DBS. Since venipuncture is time consuming, painful, and may often be difficult to achieve in newborns, the use of DBS for analysis of phenylalanine is becoming a preferred method for dietary monitoring of patients with PKU. Using a lancet, patients or their guardians collect finger capillary blood on an approved filter paper. Once collected, the filter paper with DBS is sent to the laboratory for phenylalanine analysis. In the laboratory, phenylalanine is extracted from the DBS using organic solvents. Here, we describe an LC-MS/MS method for the analysis of phenylalanine from DBS with an approximation to serum levels.
Methods in molecular biology (Clifton, N.J.)
Chromatography, Liquid; Humans; Infant, Newborn; Phenylalanine; Phenylketonurias; Solvents; Tandem Mass Spectrometry
DBS; Dried blood spot; Filter paper; PKU; Phenylalanine
Baird S, Clinton Frazee C 3rd, Garg U. Quantitation of Phenylalanine in Dried Blood Spot Using Liquid Chromatography Tandem Mass Spectrometry for Monitoring of Patients with Phenylketonuria (PKU). Methods Mol Biol. 2022;2546:391-399. doi:10.1007/978-1-0716-2565-1_34