Spherical particles composed of a special class of basic proteins in combination with DNA. The particles are approximately 12.5 mm in diameter and are connected to each other by DNA filaments. Under the electron microscope they appear somewhat like a string of pearls.
The structural subunit of chromatin, consisting of -200 bp of DNA and an octamer of histones.
The combination of positively charged histone proteins and negatively charged DNA; the first step in the folding of DNA into chromatin.