DNA supercoil introduced to directly visualize individual plectonemes along supercoiled DNA which would further allow to study the interactions of DNA processing proteins with supercoiled DNA. In that study, Sytox Orange (an intercalating dye), has been used to induce supercoiling on surface tethered DNA molecules. DNA supercoiling is important for DNA packaging within all cells. Because the length of DNA can be thousands of times that of a cell, packaging this genetic material into the cell or nucleus (in eukaryotes) is a difficult feat. Supercoiling of DNA reduces the space and allows for DNA to be packaged. In prokaryotes, plectonemic supercoils are
Extrachromosomal DNA that cell matures and expands, containing fully mature plastids. Extrachromosomal circular DNA (eccDNA) is present in all eukaryotic cells, is usually derived from genomic DNA, and consists of repetitive sequences of DNA found in both coding and non-coding regions of chromosomes. EccDNA can vary in size from less than 2000 base pairs to more than 20,000 base pairs. In plants, eccDNA contains repeated sequences similar to those that are found in the centromeric regions of the chromosomes and in repetitive satellite DNA. In animals, eccDNA molecules have been shown to contain repetitive sequences that are seen in satellite DNA, 5S