Atomic force microscope imaging of chromosome structure during G-banding treatments.

Surface topography of human chromosomes was examined by atomic force microscopy during treatments for G-banding. Trypsin treatment resulted in a structural modification in the chromatin. Subsequent Giemsa staining caused a general swelling of the chromosomal surface that was greater in the areas of G-band positive regions. By means of a quantitative evaluation method we showed that the G-banding process produces a 10-fold enhancement of a pre-existing pattern of chromatin between G-band positive and G-band negative regions on mitotic chromosomes.