Adamczyk Thomasz, Doescher Andrea, Haydock Paul V, Aldrich Russ, Petershofen Eduard K, Müller Thomas H
Medical Hospital 'Links der Weser', Gesundheit Nord, Department Internal Medicine, Bremen, Germany.
German Red Cross Blood Transfusion Service NSTOB, Institute Oldenburg, Germany.
Transfus Med Hemother. 2015 Nov;42(6):379-84. doi: 10.1159/000441542. Epub 2015 Oct 26.
Determination of fetal blood groups in maternal plasma samples critically depends on adequate pre-analytical steps for optimal amplification of fetal DNA. We compared the extraction of cell-free DNA by binding on a glass surface (BCSI SNAP™ Card) with an automated system based on bead technology (MagnaPure compact™).
Maternal blood samples from 281 pregnancies (7th-39th week of gestation) with known antibodies were evaluated in this study. Both the SNAP card and the MagnaPure method were applied to isolate DNA in order to directly compare the amplification in a single base extension assay and/or real-time PCR.
The mean concentration of total DNA obtained by the SNAP card (33.8 ng/µl) exceeded more than twofold that of MagnaPure extraction (15.7 ng/µl). SNAP card-extracted samples allowed to detect 3.7 single nucleotide polymorphisms (SNPs) versus 2.5 SNPs in MagnaPure extracts to control for traces of fetal DNA. This difference is highest for samples from 7th-13th week of gestation.
The SNAP card system improves DNA extraction efficacy for prenatal diagnosis in maternal blood samples and provides an at least eightfold higher total amount of DNA for the ensuing analysis. Its advantage is most evident for samples from early stages of pregnancy and thus especially valuable for pregnancies with antibodies.
在母血样本中确定胎儿血型严重依赖于适当的分析前步骤，以实现胎儿DNA的最佳扩增。我们将基于玻璃表面结合（BCSI SNAP™卡）的游离DNA提取方法与基于磁珠技术的自动化系统（MagnaPure compact™）进行了比较。
本研究评估了281例已知抗体的妊娠（妊娠第7至39周）的母血样本。应用SNAP卡和MagnaPure方法分离DNA，以便在单碱基延伸分析和/或实时PCR中直接比较扩增情况。
SNAP卡获得的总DNA平均浓度（33.8 ng/µl）比MagnaPure提取法（15.7 ng/µl）高出两倍多。SNAP卡提取的样本可检测到3.7个单核苷酸多态性（SNP），而MagnaPure提取物中可检测到2.5个SNP，以控制胎儿DNA的痕迹。这种差异在妊娠第7至13周的样本中最为明显。
SNAP卡系统提高了母血样本产前诊断的DNA提取效率，并为后续分析提供了至少高出八倍的DNA总量。其优势在妊娠早期样本中最为明显，因此对有抗体的妊娠尤其有价值。
