Source:http://linkedlifedata.com/resource/umls/id/C1516511
NCI: The more readily stainable portion of the cell nucleus, forming a network of nuclear fibrils within the achromatin of a cell. It is a deoxyribonucleic acid attached to a protein (primarily histone) structure base and is the carrier of genes in inheritance. It occurs in two states, euchromatin and heterochromatin, with different staining properties, and during cell division, it coils and folds to form the chromosomes.