Test ID: AGABS
Alpha-Galactosidase, Blood Spot
Method Description
Describes how the test is performed and provides a method-specific reference
Whole blood is collected on grade 903 (Whatman) filter paper. A one-eighth inch (3-mm) disk is punched out of the dried blood spot into a 96-well plate. 20 mcL of 0.25 M N-acetyl-D-galactosamine is added as elution liquid/inhibitor and 50 mcL of 5 mM 4-methylumbelliferyl-alpha-D-galactopyranoside in 0.15 M cit-phos buffer as the substrate (70 mcL total volume plus dried blood spot). After the incubation period (20 hours at 37 degrees C), all of the liquid from the plate is manually transferred to a second 96-well plate. 200 mcL of stop buffer (150 mM EDTA, pH 11.4) is added to all wells. A calibration is added to every plate and is derived from 4-methylumbelliferone (4-MU) that is serially diluted manually in the plate with the highest calibrator being equivalent to an enzyme activity of 12.2 nmol/mL/hr. The plate is then read on the spectrofluorometer. Fluorescence readings for duplicate wells are averaged and the average fluorescence is used to calculate the enzyme activity result. (Poeppl AG, Murray GJ, Medin JA: Enhanced filter paper enzyme assay for high-throughput population screening for Fabry disease. Anal Biochem 2005;337:161-163)
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.
Thursday; morning


