Minibands and chromosome structure. A theory.

Bright and dark field microscopy were used to examine interphase nuclei and RBG-banded human chromosomes. In dark field microscopy both chromosomes and interphase chromatin appeared to be composed of similar independent structures alternating between bright and dull light intensity. The position, colour, and number of these structures may support the theory that the transition from interphase chromatin to metaphase chromosomes, takes place without any dramatic changes in local chromatin structure. Although the resolution power of bright and dark field microscopy prevent a direct proof for the miniband model, our observations in combination with other data may add further support to this particular model of chromosome organization.