Cord blood buffy coat DNA methylation is comparable to whole cord blood methylation

Cord blood DNA methylation is associated with numerous health outcomes and environmental exposures. Whole cord blood DNA reflects all nucleated blood cell types, while centrifuging whole blood separates red blood cells by generating a white blood cell buffy coat. Both sample types are used in DNA methylation studies. Cell types have unique methylation patterns and processing can impact cell distributions, which may influence comparability. To evaluate differences in cell composition and DNA methylation between buffy coat and whole cord blood samples, cord blood DNA methylation was measured with the Infinium EPIC BeadChip (Illumina) in 8 individuals, each contributing buffy coat and whole blood samples. 16 cord blood samples, 8 buffy coat and 8 whole blood paired by individual, were assayed on the Infinium EPIC BeadChip (Illumina)