IMAGING OF DNA IN HUMAN AND PLANT CHROMOSOMES BY HIGH-RESOLUTION SCANNING ELECTRON-MICROSCOPY

We describe a DNA-specific staining procedure, using a blue platinum o rganic dye, which allows DNA imaging of chromosomes by detection of ba ck-scattered electrons in the scanning electron microscope. DNA distri bution is visualized within chromosomal details of the centromeric and satellite regions, or in interphase chromatin, with high-resolution ( 10-15 nm) for comparison with the corresponding secondary electron ima ge representing DNA plus protein.