The fine structure of isolated metaphase chromosomes

Abstract

Chromosomes have been isolated directly from cells in metaphase for study under the electron microscope by spreading on a Langmuir trough, followed by critical point drying. The morphology of metaphase chromosomes obtained by this method, when compared with the chromosome-like threads isolated from cells by the Waring blender method, indicates that the latter are artifacts resulting from the distortion of interphase nuclei by the blender. The presence in the blender isolate of various stages in the conversion of interphase nuclei to chromosome-like elongated masses supports this interpretation. Because the blender threads show a fibrous fine structure similar to the basic 250–280 Å fibers making up interphase nuclei and metaphase chromosomes isolated by the Langmuir trough method, they are considered to be of nuclear origin, which would account for their staining characteristics.