|
Similar to the mitochondrion, the nucleus has a double membrane. The inner and outer nuclear membranes enclose the perinuclear space. The outer membrane may be continuous with the rough endoplasmic reticulum (RER). Attached to the inner nuclear membrane is a fibrous layer known as the nuclear lamina or fibrous lamina. Nuclear pores are dispersed throughout the membrane and represent areas where the two membranes meet.
The nucleus contains the DNA of the cell. Under electron microscopy, the genetic material may be visualized as the transcriptionally-inactive heterochromatin along the periphery of the nucleus. The transcriptionally active euchromtain is invisible. Under light microscopy, the nucleus is stained blue by hematoxylin. Hematoxylin is a basic dye that binds to the basophilic nucleic acids.
|