title: Impact of various factors on radioactivity distribution in different DBS papers.
abstract: BACKGROUND
  Dried blood spot (DBS) sampling could potentially become the preferred blood collection technique in toxicological and clinical studies. Autoradiography was performed to study compound distribution within a dbs under different conditions using five papers, 31ETF, Grade 226, 903(®), FTA(®) and FTA(®) Elute.
  
  
  RESULTS
  The results showed an uneven distribution in all papers with common distribution patterns regardless of compounds: decreased concentrations along the edge, the volcano effect in the middle and the speckle pattern in the center. Treated papers were more readily influenced by environmental factors.
  
  
  CONCLUSIONS
  Autoradiography enables visualization of a compound's distribution and can guide bioanalytical assay development by allowing convenient evaluation of factors, such as choice of paper, spotting volume, punch size, punch location, temperature and humidity.
authors.affiliation: Drug Disposition, Safety and Animal Research, sanofi-aventis, Bridgewater, NJ, USA. xiao.ren@sanofi-aventis.com
authors.forename: Xiao
authors.initials: X
authors.lastname: Ren
authors.forename: Tobias
authors.initials: T
authors.lastname: Paehler
authors.forename: Manfred
authors.initials: M
authors.lastname: Zimmer
authors.forename: Zuyu
authors.initials: Z
authors.lastname: Guo
authors.forename: Patricia
authors.initials: P
authors.lastname: Zane
authors.forename: Gary T
authors.initials: GT
authors.lastname: Emmons
mesh_terms: D000328:Adult; D001774:Blood Chemical Analysis / Q000379:methods*; D001777:Blood Coagulation; D001800:Blood Specimen Collection / Q000295:instrumentation*; D055598:Chemical Phenomena; D003890:Desiccation; D006400:Hematocrit; D006801:Humans; D006813:Humidity; D007753:Laboratories; D008297:Male; D010209:Paper; D011851:Radioactivity; D013696:Temperature