We describe a process for fixation, embedding, sectioning, and imaging of late stage Drosophila embryos for Trasmission Electron Microscopy of the embryonic heart tube. This technique allows for the visualization of the heart tube lumen as well as the basement membrane, which lines the lumen of the heart.
Soplop, N. H., Patel, R., Kramer, S. G. Preparation of embryos for Electron Microscopy of the Drosophila embryonic heart tube. J. Vis. Exp. (34), e1630, doi:10.3791/1630 (2009).