Genes inside the cell follow several layers of organisation to enable the long DNA to be compacted into the chromosome fibers. In the first level of packing, DNA is wrapped around 4 pairs of proteins called Histones in a “beads-on-string” fashion.

These nucleosomes then coil around each other in the form of a helix, with around 6 nucleosomes forming one turn of a helix.

These helices form the long chromatin fibers which, with series of turns and loops, forms the third level of spatial DNA organisation.

Finally, these chromatin fibers are compactly packed inside the chromosome. In the Chromosome, the chromatin fibers are wrapped around a protein scaffold.