title: Improvement in fetal DNA extraction from maternal plasma. Evaluation of the NucliSens Magnetic Extraction system and the QIAamp DSP Virus Kit in comparison with the QIAamp DNA Blood Mini Kit.
abstract: OBJECTIVE
  Prenatal diagnostic assays have been developed using free fetal DNA circulating in the maternal blood of pregnant women. Efficient DNA extraction is crucial for a robust analysis. To improve fetal DNA yield, we tested two manual extraction methods--the NucliSens Magnetic Extraction (NMAG) system and the QIAamp DSP Virus Kit (QDSP)--against our current standard method, the widely used QIAamp DNA Blood Mini Kit (QDNA).
  
  
  METHODS
  The fetal DNA yield of the two extraction systems was evaluated using the RHD exon 7 as target in DNA extracts of 75 plasma samples from pregnant RhD-negative women, known to have given birth to RhD-positive infanto. The total DNA yield was evaluated in 23 samples, targeting GAPDH.
  
  
  RESULTS
  The fetal DNA yield was improved by a mean factor of 1.7 using the NMAG system, and improved by a mean factor of 1.5 using the QDSP. The total DNA yield was improved by a mean factor of 2.3 using the NMAG system, and by a mean factor of 1.3 using the QDSP.
  
  
  CONCLUSIONS
  Both extraction systems tested were superior to our standard with regard to DNA yield. This improvement may have a great impact on the success of genotyping in early pregnancy.
authors.affiliation: H:S Blodbank KI2034, Copenhagen University Hospital, Copenhagen, Denmark. frederik.banch.clausen@rh.hosp.dk
authors.forename: Frederik Banch
authors.initials: FB
authors.lastname: Clausen
authors.forename: Grethe Risum
authors.initials: GR
authors.lastname: Krog
authors.forename: Klaus
authors.initials: K
authors.lastname: Rieneck
authors.forename: Morten Hanefeld
authors.initials: MH
authors.lastname: Dziegiel
mesh_terms: D004247:DNA / Q000097:blood*; D005091:Exons; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005331:Fetomaternal Transfusion / Q000097:blood*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D006801:Humans; D008280:Magnetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D011933:Reagent Kits, Diagnostic; D012204:Rh-Hr Blood-Group System / Q000235:genetics
chemical_list: D011933:Reagent Kits, Diagnostic; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases