Speaker: Tanya Prozorov, Associate Scientist at Ames Laboratory
Title: Liquid Phase Electron Microscopy Characterization of Biological and Soft Materials
Abstract: Microscopy aided in many important discoveries in life sciences. Our early work focused on a correlative S/TEM and fluorescence microscopy technique for imaging viable cells of Magnetospirillum magneticum strain AMB-1 in liquid phase in situ using a commercially available fluid cell TEM holder. Bacterial magnetite biomineralization is a complex and not fully understood process, and exploring new analytical approaches of characterization in situ opens new ways for the studies of dynamic processes in single cells with nanometer-scale resolution. This approach permits imaging fully hydrated cells of various biological and soft matter specimens in their natural fully hydrated environment. And while the crystal structure of magnetosome magnetite is well-established, far less is known about internal magnetic order and magnetic interactions between magnetosome magnetite nanocrystals in bacteria’s native liquid environment. We expanded the in situ characterization of magnetotactic bacteria to include off axis electron holography of bacterial cells and magnetic nanocrystals in liquid. I will outline the challenges and opportunities this latest development opens in the field of in situ EM imaging in liquid phase. I will outline the latest development in liquid phase electron microscopy of soft materials in situ and discuss the ways to minimize the electron beam damage to the specimen. The findings obtaining with using magnetotactic bacteria as model system lend themselves naturally to the investigation of many real-world samples. Our current liquid phase electron microscopy effort is focused on expanding this approach to imaging of other systems, spanning from characterization of gel-based nanocomposites, DNA-templated nanoparticle growth, to visualization of unstained DNA origami nanostructures and metallization of DNA origami triangles by the electron beam in situ.
Bio: https://faculty.sites.iastate.edu/tprozoro/research
Seminar Host: Xiaoli Tan