Porphobilinogen, Quantitative, Random, Urine
Method Description Describes how the test is performed and provides a method-specific reference
Porphobilinogen (PBG) in urine is quantified by liquid chromatography tandem-mass spectrometry analysis in positive ion mode. An internal standard (13C2-PBG) is added to 1 mL of acidified urine. PBG and 13C2-PBG are extracted from the sample using an Oasis HLB column on a Gilson ASPEC Workstation. Separation of PBG from the specimen matrix is achieved by a reverse phase HPLC. PBG and the internal standard are monitored through their corresponding precursor and product ion pairs. The ion pair for PBG and 13C2-PBG are m/z 227 to m/z 210 and m/z 229 to m/z 212, respectively.(Ford RE, Magera MJ, Kloke KM, et al: Quantitative measurement of porphobilinogen in urine by stable-isotope dilution liquid chromatography-tandem mass spectrometry. Clin Chem 2001 September;47:1627-1632)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 8 a.m.