Mitochondrial DNA Mitochondrial DNA Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. In humans, the 16,569 base pairs of mitochondrial DNA encode for only 37 genes. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. In
Cell-free fetal DNA of laboratory methods have been developed for cell-free fetal DNA screening for genetic defects have been developed. The main ones are (1) massively parallel shotgun sequencing (MPSS), (2) targeted massive parallel sequencing (t-MPS) and (3) single nucleotide polymorphism (SNP) based approach. A maternal peripheral blood sample is taken by venesection at about ten weeks gestation. Blood plasma is separated from the maternal blood sample using a laboratory centrifuge. The cffDNA is then isolated and purified. A standardized protocol for doing this was written through an evaluation of the scientific literature. The highest yield in cffDNA extraction was obtained with the