The document discusses how DNA is packed into eukaryotic chromosomes. DNA first wraps around histone proteins to form nucleosomes, compacting the DNA 7-fold. Nucleosomes then interact to form a 30nm fiber compacting the DNA another 7-fold. Additional compaction occurs through interactions between the 30nm fiber and the nuclear matrix, forming radial loop domains that attach to the nuclear lamina and internal matrix, further condensing the DNA. This hierarchical packaging allows the long eukaryotic chromosomes to fit within the nucleus.