Prof. Dr. Walter represents the focus "Biophotonics" of the study programs "Bachelor Optical Engineering" and "Master Applied Photonics". His main interests lie in advancing bioimaging & biophotonics. The Group of Prof. Dr. Walter aims at developing novel correlative microscopy solutions to facilitate imaging across scales in life sciences. Specifically, we plan to combine advanced fluorescence microscopy with electron microscopy to visualize molecules within their subcellular context at high resolution using Correlative Light and Electron Microscopy (CLEM). Specifically, we envision a unique advanced super-resolution and volume CLEM workflow under cryo-conditions (Correlative Cryo-Super-Resolution Light and Focused Ion Beam Scanning Electron Microscopy) that pushes correlative microscopy further and allows us, together with our collaboration partners, to tackle specific biomedical research questions that could not be answered before due to the lack of accessible solutions (ranging from nanodrugs to nanoplastics).

Our vision is to develop advanced multimodal imaging pipelines to zoom in from endogenous tissue or even living organisms to individual subcellular structures and relate their molecular dynamics to their overall anatomy.

We are a highly interdisciplinary group between physicis, engineering, optics and life sciences and have several open positions available ranging from optical setups of home-built microscopes to automating image acquisition protocols for biological samples.

  • Grant Manager COMULIS: Daniela Kuzdas-Wood
  • Scientific Assistant & Research Master: Louisa Leitgeb

Keuenhof,  K.S., Kavirayani, A., Reier, S., Geyer, S.H., Weninger, W.J., Walter, A.*, ‘High-Resolution Episcopic Microscopy (HREM) in Multimodal Imaging Approaches.’ Biomedicines (2022) – *Corresponding Author

Walter, A.*, Mannheim, J., Caruana, C., ‘Imaging Modalities in Biological and Preclinical Research: A Compendium.’ IoP-IPEM ebook series in Physics & Engineering in Medicine & Biology (2021) – *Volume Editor

Walter, A.*, Paulino, C., Heuser, T., ‘Cryo-Electron Microscopy’ in ‘Imaging Modalities in Biological and Preclinical Research: A Compendium.’ IoP-IPEM ebook series in Physics & Engineering in Medicine & Biology (2021)

Walter, A.*, Stylianou, A., ‘Light Microscopy’ in ‘Imaging Modalities in Biological and Preclinical Research: A Compendium.’ IoP-IPEM ebook series in Physics & Engineering in Medicine & Biology (2021) 

Walter, A.*, Pereiro, E., Harkiolaki, M., ‘Soft X-Ray Microscopy’ in ‘Imaging Modalities in Biological and Preclinical Research: A Compendium.’ IoP-IPEM ebook series in Physics & Engineering in Medicine & Biology (2021) 

Verkade, P., Collinson, L., Munoz-Baruttia, A., Walter, A.*, ‘Emerging Imaging Technologies & Outlook’ in ‘Imaging Modalities in Biological and Preclinical Research: A Compendium.’ IoP-IPEM ebook series in Physics & Engineering in Medicine & Biology (2021) 

Karreman, M., Pacureanu, A., Bosch Pinol, C., Schaefer, A., Walter, A.*, ‘Correlated Multimodality Imaging Across Scales’ in ‘Imaging Modalities in Biological and Preclinical Research: A Compendium.’ IoP-IPEM ebook series in Physics & Engineering in Medicine & Biology (2021)

Reier, S., Turyanskaya, A., Heimel, P., Frischauf, N., Meusburger, D., Heuser, T., Drexler, N., Cristina, S., Plochberger, B., Slezak, P.,  Dungel, P., Slezak, P., Szabo, A., Walter, A.*, ‘Cross-Modality Imaging of Bisphosphonate-Treated Murine Jawbones.’ Analyst, 146: 4683-4699 (2021) – *Corresponding Author

Zopf, L., Jelena, Z., Mitterhauser, M., Helbich, T., Mengyang, L., Slezak, P., Weninger, W., Geyer, S., Kavirayani, A., Buehler, K., Walter, A.*, ‘Cross-Modality Imaging of Murine Tumor Vasculature – A Feasibility Study.’ Molecular Imaging & Biology (2021)

Keuenhofer, K., Macfelda, K., Streli, C., Schoefer, C., Weninger, W., Geyer, S., Slezak, P., Zopf, L., Wanek, T., Walter, A.*, ‘Multimodality imaging beyond CLEM: Showcases of combined in-vivo preclinical imaging and ex-vivo microscopy to detect murine mural vascular lesions.’ Methods in Cell Biology, 162:389-415 (2021) 

Walter, A., Verkade, P., ‘Community Efforts and Research Infrastructure for (Multimodality) BioImaging.’ Methods in Cell Biology, 162: 417-430 (2020)

Walter, A.*, Paul-Gilloteaux, P., Plochberger, B., Verkade, P., Sefc, L., Mannheim, J., Unterhuber, A., Ogris, M., Marchetti-Deschmann, M., Handschuh, S., Dror, F., ‘Correlated Multimodality Imaging: Expanding the Biomedical Horizon.’ Front. Phys. 8:47 (2020) – *Corresponding Author

Roth, M., Gallaher, S., Westcott, D., Iwai, M., Louie, K., Mueller M., Walter, A., Foflonker, F., Bowen, B., Ataii, N., Song J., Chen J., Blaby-Haas, C., Larabell, C., Auer, M., Northern T., Merchant, S., Niyogi, K., ‘Regulation of Oxygenic Photosynthesis during Trophic Transitions in the Green Alga Chromochloris zofingiensis.’ Plant Cell, 31:579–60 (2019)

Roth, M., Cokus, J., Walter, A., Gallaher, S., Lopez, D., Erickson, E., Endelman, B., Westcott, D., Larabell, C., Merchant, S., Pellegrini, M., Niyogi, K., ‘Chromosome-level genome assembly and transcriptome of the green alga Chromochloris zofingiensis illuminates astaxanthin production.‘ Proc. Natl. Acad. Sci. USA (2017)

Walter, A., Steltenkamp, S., Schmitz, S., Holik, P., Sachser, R., Huth, M., Rhinow, D., Kühlbrandt, W., ‘Towards an optimum design for electrostatic phase plates.‘ Ultramicroscopy, 153:22-31 (2015)

Gold, V., Raffaele, I., Walter, A., Pfanner, N., van der Laan, M., Kühlbrandt, W., ‘Visualizing active membrane protein complexes by electron cryotomography.‘ Nature Communications, 5:4129 (2014)

Walter, A., Chapuis, C., Huet, S., Ellenberg, J., ‘Crowded chromatin is not sufficient for heterochromatin formation and not required for its maintenance.‘ Journal of Structural Biology, 184:445-453 (2013)

Daum, B., Walter, A., Horst, A., Osiewacz, H., Kühlbrandt, W., ‘Age-dependent dissociation of ATP synthase dimers and loss of inner-membrane cristae in mitochondria.‘ Proc. Natl. Acad. Sci. USA, 110:15301-15306 (2013)

Walter, A., Muzik, H., Vieker, H., Turchanin, A., Beyer, A., Gölzhäuser, A., Lacher, M., Steltenkamp, S., Schmitz, S., Holik, P., Kühlbrandt, W., Rhinow, D., ‘Practical aspects of Boersch phase contrast electron microscopy of biological specimens.‘ Ultramicroscopy, 116:62-72 (2012)

Barton, B., Rhinow, D., Walter, A., Schröder, R., Benner, G., Majorovits, E., Niebel, H., Müller, H., Haider, M., Lacher, M., Schmitz, S., Holik, P., Kühlbrandt, W., ‘In-focus electron microscopy of frozen-hydrated biological samples with a Boersch phase plate.‘ Ultramicroscopy, 111:1696-1705 (2011)

Open positions and student research projects of this working group and the ZOT can be found here.

COMULIS (Correlated Multimodal Imaging in Life Sciences) is an EU-funded COST Action that aims at fueling urgently needed collaborations in the field of correlated multimodal imaging (CMI), promoting and disseminating its benefits through showcase pipelines, and paving the way for its technological advancement and implementation as a versatile tool in biological and preclinical research. CMI combines two or more imaging modalities to gather information about the same specimen. It creates a

composite view of the sample with multidimensional information about its macro-, meso- and microscopic structure, dynamics, function and chemical composition. Since no single imaging technique can reveal all these details, CMI is the only way to understand biomedical processes and diseases mechanistically and holistically. CMI relies on the joint multidisciplinary expertise from biologists, physicists, chemists, clinicians and computer scientists, and depends on coordinated activities and knowledge transfer between academia and industry, and instrument developers and users. Due to its inherently multidisciplinary and crossfunctional nature, an interdisciplinary network such as this Action is indispensable for the success of CMI. Nevertheless, there is currently no European network in the field. Existing scattered efforts focus on correlated light and electron microscopy or (pre)clinical hybrid imaging. This Action will consolidate these efforts, establish commonly-accepted protocols and quality standards for existing CMI approaches, identify and showcase novel CMI pipelines, bridge the gap between preclinical and biological  imaging, and foster correlation software through networking, workshops and open databases. The network will raise awareness for CMI, train researchers in multimodal approaches, and work towards a scientific mindset that is enthusiastic about interdisciplinary imaging approaches in life sciences.