title: Optimized DNA extraction from neonatal dried blood spots: application in methylome profiling.
abstract: BACKGROUND
  Neonatal dried blood spots (DBS) represent an inexpensive method for long-term biobanking worldwide and are considered gold mines for research for several human diseases, including those of metabolic, infectious, genetic and epigenetic origin. However, the utility of DBS is restricted by the limited amount and quality of extractable biomolecules (including DNA), especially for genome wide profiling. Degradation of DNA in DBS often occurs during storage and extraction. Moreover, amplifying small quantities of DNA often leads to a bias in subsequent data, particularly in methylome profiles. Thus it is important to develop methodologies that maximize both the yield and quality of DNA from DBS for downstream analyses.
  
  
  RESULTS
  Using combinations of in-house-derived and modified commercial extraction kits, we developed a robust and efficient protocol, compatible with methylome studies, many of which require stringent bisulfite conversion steps. Several parameters were tested in a step-wise manner, including blood extraction, cell lysis, protein digestion, and DNA precipitation, purification and elution. DNA quality was assessed based on spectrophotometric measurements, DNA detectability by PCR, and DNA integrity by gel electrophoresis and bioanalyzer analyses. Genome scale Infinium HumanMethylation450 and locus-specific pyrosequencing data generated using the refined DBS extraction protocol were of high quality, reproducible and consistent.
  
  
  CONCLUSIONS
  This study may prove useful to meet the increased demand for research on prenatal, particularly epigenetic, origins of human diseases and for newborn screening programs, all of which are often based on DNA extracted from DBS.
authors: Akram
authors: A
authors: Ghantous
authors: Richard
authors: R
authors: Saffery
authors: Marie-Pierre
authors: MP
authors: Cros
authors: Anne-Louise
authors: AL
authors: Ponsonby
authors: Steven
authors: S
authors: Hirschfeld
authors: Carol
authors: C
authors: Kasten
authors: Terence
authors: T
authors: Dwyer
authors: Zdenko
authors: Z
authors: Herceg
authors: Epigenetics Group, International Agency for Research on Cancer (IARC), 150 rue Albert-Thomas, 69008 Lyon, France. vargash@iarc.fr.
authors: Hector
authors: H
authors: Hernandez-Vargas
mesh_terms: D018070:Biological Specimen Banks; D002460:Cell Line; D016000:Cluster Analysis; D004247:DNA / Q000097:blood* / Q000302:isolation & purification; D019175:DNA Methylation; D059788:Dried Blood Spot Testing; D006801:Humans; D007231:Infant, Newborn; D013053:Spectrophotometry
chemical_list: D004247:DNA