title: The effect of preparation, storage and shipping of dried blood spots on the activity of five lysosomal enzymes.
abstract: BACKGROUND
  Fluorometric and tandem mass spectrometry assays can be used to measure lysosomal enzyme activities in dried blood spots (DBS). The effect of DBS preparation, storage and shipping was evaluated on the activities of acid α-glucosidase, acid α-galactosidase, acid β-glucocerebrosidase, acid sphingomyelinase, and galactocerebrosidase.
  
  
  METHODS
  Whole blood from normal donors was used to prepare DBS following Clinical and Laboratory Standards Institute guidelines and by several deviations. Some DBS were subjected to various treatments, storage and shipping conditions. The activity of 5 lysosomal enzymes (GAA, GLA, GBA, ASM, and GALC) was measured using tandem mass spectrometric and fluorometric (GAA only) assays with 2 distinct and commonly used synthetic substrates.
  
  
  RESULTS
  Enzyme activities were strongly affected by the way DBS were prepared and stored. Exposure of DBS to elevated heat and humidity can destroy enzyme functions rapidly. DBS prepared from poorly mixed blood caused significant variation on enzyme activities. EDTA, but not heparin, as an anti-coagulant gave more precise results.
  
  
  CONCLUSIONS
  The study confirmed the importance of proper and consistent DBS preparation and storage when screening for deficiencies of lysosomal enzymes.
authors.affiliation: Genzyme Corporation, P O Box 9322, Framingham, MA 01701, United States.
authors.forename: Carole S
authors.initials: CS
authors.lastname: Elbin
authors.forename: Petra
authors.initials: P
authors.lastname: Olivova
authors.forename: Carla A
authors.initials: CA
authors.lastname: Marashio
authors.forename: Samantha K
authors.initials: SK
authors.lastname: Cooper
authors.forename: Emmaline
authors.initials: E
authors.lastname: Cullen
authors.forename: Joan M
authors.initials: JM
authors.lastname: Keutzer
authors.forename: X Kate
authors.initials: XK
authors.lastname: Zhang
mesh_terms: D000328:Adult; D053000:Analytic Sample Preparation Methods / Q000295:instrumentation / Q000379:methods*; D001777:Blood Coagulation / Q000187:drug effects; D001800:Blood Specimen Collection / Q000295:instrumentation / Q000379:methods*; D001810:Blood Volume; D004492:Edetic Acid / Q000494:pharmacology; D057075:Enzyme Assays / Q000295:instrumentation / Q000379:methods*; D005374:Filtration; D005470:Fluorometry; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D006867:Hydrolases / Q000097:blood* / Q000378:metabolism*; D008247:Lysosomes / Q000201:enzymology*; D010209:Paper; D053719:Tandem Mass Spectrometry; D013696:Temperature
chemical_list: D006493:Heparin; D004492:Edetic Acid; D006867:Hydrolases