title: Comparison of four methods for extracting DNA from dried blood on filter paper for PCR targeting the mitochondrial Plasmodium genome.
abstract: BACKGROUND
  Few studies comparing multiple methods for DNA extraction from dried blood spots (DBS) on filter paper for PCR targeting the Plasmodium genome have been done.
  
  
  METHODS
  Frequently-used methods for DNA extraction from DBS using Chelex-100, InstaGene Matrix, QIAamp DNA Mini Kit and TE buffer were compared on a dilution series of a standardized Plasmodium falciparum positive sample. The two DNA extraction methods resulting in the lowest limits of detection were compared by testing both on 31 P. falciparum positive samples collected under field conditions and stored for 4 years.
  
  
  RESULTS
  The Chelex-100, InstaGene Matrix and QIAamp DNA Mini Kit methods performed similarly, resulting in the detection of 0.5 to 2 parasites per microliter (p/µl). The same 13 clinical samples (13/31; 42%) were positive using both DNA extraction methods with the lowest limits of detection.
  
  
  CONCLUSIONS
  Simple and low-cost methods can be sensitive and useful in extracting DNA from DBS. Poor results on stored clinical DBS indicate that further studies on the impact of storage duration and conditions, and choice of filter paper should be performed.
authors.affiliation: Department of Clinical Science, University of Bergen, 5020 Bergen, Norway National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway gro_strom@hotmail.com.
authors.forename: Gro E A
authors.initials: GE
authors.lastname: Strøm
authors.affiliation: Department of Clinical Science, University of Bergen, 5020 Bergen, Norway National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway.
authors.forename: Marit G
authors.initials: MG
authors.lastname: Tellevik
authors.affiliation: Department of Clinical Science, University of Bergen, 5020 Bergen, Norway National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway.
authors.forename: Kurt
authors.initials: K
authors.lastname: Hanevik
authors.affiliation: Department of Clinical Science, University of Bergen, 5020 Bergen, Norway Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Langeland
authors.affiliation: Department of Clinical Science, University of Bergen, 5020 Bergen, Norway National Centre for Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Blomberg
mesh_terms: D016054:DNA, Protozoan / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology*; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods*; D013048:Specimen Handling / Q000379:methods
chemical_list: D016054:DNA, Protozoan
keywords: Chelex; Dried blood spot testing; Malaria; Mitochondrial genome; PCR