title: Does Formaldehyde Increase Cell Free DNA in Maternal Plasma Specimens?
abstract: BACKGROUND
  There have been conflicting observations reported in the literature regarding the effects of formaldehyde in the recovery of cell free fetal DNA (CFF DNA) from maternal plasma. The aim of the present study was to assess the effect of formaldehyde treatment on circulating cell free DNA.
  
  
  METHODS
  We conducted this study using blood specimens collected from 11 pregnant women, each of whom was carrying a male fetus. DYS14 and HBB real time assays were performed to quantify fetal and total circulating cell free DNA from formaldehyde treated and untreated maternal plasma specimens, respectively.
  
  
  RESULTS
  The concentration of total circulating cell free DNA in formaldehyde-treated maternal plasma was reduced, compared with untreated maternal plasma (n = 11; P = .02). The percentage of CFF DNA between formaldehyde-treated and untreated maternal plasma specimens did not differ significantly (n = 11; P = .15).
  
  
  CONCLUSIONS
  Addition of formaldehyde does not significantly enhance the proportion of cell free fetal DNA when blood specimens are processed without delay.
authors: Centre of Medical Genetics, Sir Ganga Ram Hospital, New Delhi, India rintuj16@yahoo.co.in.
authors: Rintu R
authors: RR
authors: Jacob
authors: Centre of Medical Genetics, Sir Ganga Ram Hospital, New Delhi, India.
authors: Renu
authors: R
authors: Saxena
authors: Centre of Medical Genetics, Sir Ganga Ram Hospital, New Delhi, India.
authors: Ishwar C
authors: IC
authors: Verma
mesh_terms: D000073888:Cell-Free Nucleic Acids / Q000032:analysis*; D004202:Disinfectants / Q000008:administration & dosage*; D005260:Female; D005557:Formaldehyde / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D010949:Plasma / Q000737:chemistry*; D011247:Pregnancy; D011309:Preservation, Biological / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D000073888:Cell-Free Nucleic Acids; D004202:Disinfectants; D005557:Formaldehyde
keywords: TaqMan probes; cell free fetal DNA; circulating cell free DNA; formaldehyde; maternal plasma; noninvasive prenatal diagnosis; real time PCR