Cell cycle Cell cycle The cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells. In bacteria, which lack a cell nucleus, the cell cycle is divided into the B, C, and D periods. The B period extends from the end of cell division to the beginning of DNA replication. DNA replication occurs during the C period. The D period refers to the stage between the end of DNA replication and the splitting of the bacterial cell into two daughter
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