title: High throughput non-invasive determination of foetal Rhesus D status using automated extraction of cell-free foetal DNA in maternal plasma and mass spectrometry.
abstract: OBJECTIVE
  To examine the potential high throughput capability and efficiency of an automated DNA extraction system in combination with mass spectrometry for the non-invasive determination of the foetal Rhesus D status.
  
  
  METHODS
  A total of 178 maternal plasma samples from RHD-negative pregnant women were examined, from which DNA was extracted using the automated Roche MagNA Pure system. Presence of the foetal RHD gene was detected by PCR for RHD exon 7 and subsequent analysis using the Sequenom MassArray mass spectrometric system.
  
  
  RESULTS
  We determined that as little as 15 pg of RHD-positive genomic DNA could be detected in a background of 585 pg of RHD-negative genomic DNA. The analysis of the clinical samples yielded a sensitivity and specificity of 96.1 and 96.1%, respectively.
  
  
  CONCLUSIONS
  Our study indicated that automated DNA extraction in combination with mass spectrometry permits the determination of foetal Rhesus D genotype with an accuracy comparable to the current approaches using real-time PCR.
authors.affiliation: Department Biomedicine, University Women's Hospital, Basel, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Grill
authors.forename: Irina
authors.initials: I
authors.lastname: Banzola
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Tea
authors.initials: T
authors.lastname: Rekhviashvili
authors.forename: Tobias J
authors.initials: TJ
authors.lastname: Legler
authors.forename: Sina P
authors.initials: SP
authors.lastname: Müller
authors.forename: Xiao Yan
authors.initials: XY
authors.lastname: Zhong
authors.forename: Sinuhe
authors.initials: S
authors.lastname: Hahn
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Holzgreve