染色质是细胞间期核内能被碱性染料染色的物质，它和染色体是同一物质在细胞周期不同阶段的存在形式。染色质主要有两种类型：在细胞分裂期凝缩而在间期松散（成为弥散状）的称为常染色质；在所有时期一直凝缩着的称为异染色质。实际上异染色质又可分为两类，一类是在各种细胞 Chromatin is a substance that can be stained with basic dyes in the interphase nucleus, which is the same form of the same substance in different stages of the cell cycle as chromosomes. There are two main types of chromatin: condensed at the cell division and loose (interspersed) interstitial called euchromatin; condensed throughout all the time known as heterochromatin. In fact heterochromatin can be divided into two categories, one is in a variety of cells