Low magnification of whole polytene chromosome from 3rd instar larva of Drosophila melanogaster imaged with high voltage EM at 1MeV showing the characteristic pattern of bands and interbands.
Salivary gland cells were squashed in 45% acetic acid, slides frozen in liquid nitrogen, cover slips removed, stained with uranyl magnesium acetate, dehydrated with ethanol, transferred to formvar coated grids, critical point dried, and imaged at 1MeV with the Wisconsin HVEM.
See Ris (1978) Preparation of chromatin and chromosomes for electron microscopy. Meth Cell Biol 18:229-246; Ris (1981) Stereoscopic microscopy of chromosomes. Meth Cell Biol 22:77-96.
Author: Hans Ris
Source: The Cell: An Image Library