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.
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.
Clausen
Frederik Banch
FB
H:S Blodbank KI2034, Copenhagen University Hospital, Copenhagen, Denmark. frederik.banch.clausen@rh.hosp.dk
Krog
Grethe Risum
GR
Rieneck
Klaus
K
Dziegiel
Morten Hanefeld
MH
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
D011933:Reagent Kits, Diagnostic; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen; D004247:DNA; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases