Placental DNA extraction
DNA extraction from placental tissue was performed according to an
adapted protocol9 from Purelink Genomic DNA commercial
kit (Life Technologies, Carlsbad, CA). DNA quality was estimated by PCR
of human CCR2 and HLAG genes. PCR products were assessed by
electrophoresis on 1.5% agarose gels stained with Blue Green Loading
Dye (LGC Biotecnologia®, São Paulo, Brazil) and then visualized by UV
light.