Mechanism of endonuclease banding of chromosomes

The restriction endonuclease BstNI markedly reduced the extent of Giemsa staining of the C-band regions of methanol/acetic acid-fixed mouse chromosomes air-dried onto glass slides. The enzyme reduced the amount of hybridizable satellite DNA correspondingly, indicating that its effects can be attributed to cutting satellite DNA into fragments short enough to be removed from fixed chromosomes.