Tomographic reconstruction from energy-filtered images of thick biological sections

SUMMARY Energy filtration makes it possible to image a ∼0.5 μm biological section at 80 kV in the electron microscope. Based on spectra taken at different tilt angles, we chose the most probable energy loss, ΔEp ± 10 eV for each tilt angle, as the imaging energy window. A complete tilt series from + 60° to −60° at 2.5° intervals was collected on the Zeiss EM902 and used in a tomographic reconstruction of transcriptionally active chromatin in the Balbiani ring of Chironomus tentans.