Abstract
A simple and reliable method for correlating EM and light microscopic observations of dividing nuclei is presented. Nuclear DNA of hyphae of Tulasnella araneosa grown on a cover glass and fixed in glutaraldehyde was stained with the DNA specific fluorochrome, mithramycin. Mitotic nuclei were identified and marked by inscribing a circle on the cover glass above the nucleus. A layer of dried agar kept the nutrient agar and hyphae bound to the cover throughout fixation, dehydration and embedding while a polytetrafluoroethylene layer allowed separation of the covery glass from the embedded hyphae prior to sectioning. In addition to allowing light microscopic and EM observations of the same nuclei, this technique reduced the sectioning effort drastically and eliminated the necessity of associating interesting nuclei with morphological markers.