Prof. Petr Chlanda: Visualizing Viral Infection by In Situ Cryo-Electron Tomography

With the advent of direct electron detectors, cryo-electron microscopy (cryo-EM) has become one of the most powerful tools in structural biology. Recent technological advances now enable the visualization of vitrified cells at molecular resolution and in a near-native state using in situ cryo-electron tomography (cryo-ET). This seminar will briefly introduce the fundamental principles of cryo-ET, cryo-focused ion beam (cryo-FIB) milling, and correlative cryo-fluorescence and electron microscopy (cryo-CLEM). Using case studies of Ebola virus and SARS-CoV-2 infected cells, I will illustrate how these approaches reveal distinct replication strategies: viruses with positive-sense RNA genomes replicate within membrane-bound organelles, whereas negative-sense RNA viruses replicate in liquid–liquid phase-separated compartments.

Petr Chlanda studied Biochemistry at Charles University in Prague. He earned his PhD at Heidelberg University, focusing on the assembly of poxviruses. During his postdoctoral research at EMBL Heidelberg and the NIH in Bethesda, he investigated the structural mechanisms of influenza A virus membrane fusion and assembly. In 2017, he became a Chica and Heinz Schaller group leader at Heidelberg University. Since 2025, he has been a Heisenberg Professor for Cryo-EM of Viral Infection at the Department of Infectious Diseases-Virology, Heidelberg University.