[Modification of chromatids before fixation: production of G bands by various stains].

Acridine orange, coriphosphine, toluidin blue, or pyronin, when added to the hypotonic solution, allow G-banding when the fixed slides are stained in the usual way. Apart from this simple practical application, these modifications of chromatid structure by a treatment applied before fixation shed some light on the molecular mechanisms responsible for chromosome banding.