DNA

DNA is the hereditary material in humans. But human DNA is almost two meters long and will not fit into the cell's nucleus. Therefore, this DNA is condensed by packaging it with proteins.

Histone octamer

Histones are positively charged proteins rich in basic amino acid residues, lysines, and arginines. These proteins bind around 200bp of negatively charged DNA into large loops to form a nucleosome.

Linker histone

The nucleosome is completed when the linker histone H1 connects to the DNA entry/exit sites on the surface of the core octamer. They appear as 'beads-on-a-string' in the nuclear chromatin.