Update: How to make your own 3D printed coronavirus model version 2

July 18, 2022
Dale Tronrud, Andrea Thorn, Philip Wehling and Yunyun Gao

The instructions and files below will allow you to create your own model of the virus! All you need is some spare time and a 3D printer. In addition, those without access to a 3D printer can still use the STL files to request printing from external services and then follow the instructions on assembling the same way. We do hope that this model will make the virus more tangible and that the model will not only be printed as a private project, but also be used for outreach activities and in educational institutions.

These instructions refer to the updated SARS-CoV-2 3D model released in early 2022 that considers new scientific insights and improves on the original. You can find details about the changes (and our reasons for them) in another blog post soon.

Our design is based on the best scientific evidence available. Not only are the shapes of the various proteins as close to the measured molecular structures as possible, but their numbers as well as the overall size of the virion match experimental results on a scale of 1:1,000,000. Therefore, 1 mm on the model represents 1 nm (10 Å).

By the way, this would make the RNA that is inside the virus hull 10 meters long and 1 mm thick.

3D preview of the model

What you need to get started

For easier printing and assembly, the virus structure has been broken down into individual components:

For the model with rigid spikes:

https://www.thingiverse.com/thing:5326932/files

- Virion (one Top and one Bottom)

The two virion components are completely solid irregular hemispheroids. The body has been broken down into two separate parts in order to produce two flat surfaces, minimizing the need for supports and lowering the amount of excess material when printing. The outer surfaces contain the necessary recesses for the spike proteins to sit in. This model contains 26 such holes. The surface of the virion is textured to represent SARS-CoV-2's E and M proteins.

- 26 Spike Proteins

The spike protein stucture provides perhaps the most challenging aspect of the printing operation. Each spike consists of a complex crown-like surface and supporting stalk which connects it to the central virion. The individual spike STL files show the spike in different conformations and at varying angles.

For the model with springs:

https://www.thingiverse.com/thing:5666273/files

- Virion (one Top and one Bottom)

The two virion components are completely solid irregular hemispheroids. The body has been broken down into two separate parts in order to produce two flat surfaces, minimizing the need for supports and lowering the amount of excess material when printing. The outer surfaces contain the necessary recesses for the spike proteins to sit in. This model contains 26 such holes. The surface of the virion is textured to represent SARS-CoV-2's E and M proteins.

- 26 Spike Proteins (11 extended, 15 retracted)

The spike protein stucture provides perhaps the most challenging aspect of the printing operation. Each spike consists of a complex crown-like surface that is mounted on a spring.

- Springs

You can purchase a suitable spring at https://www.mcmaster.com/compression-spring-stock/od~1-8/id~0-085/. This spring is 20 inches or 508 mm long. You can cut it either in 26 19mm pieces or 28 18mm pieces with two spare ones. If you want to get your springs from some other source, make sure that their outer diameter is about the same as this one (0.125 inches or 3.2 mm). The springs have to fit into the holes in the model parts.

To date, the structures have been printed successfully on several Fused Deposition Modelling (FDM) printers (Rostok MAX v2 & Prusa I3 MK3 printers), and we anticipate the even higher quality structures will be feasible with alternative methods, such as stereolithography (watch this space). Each of the parts is available in STL format and is printable through any suitable slicer software. Personal discretion is advised when setting up the prints, as the exact details may differ depending on conditions and equipment. The procedure outlined below will serve as a good starting point. Let us know of your experience in the comments!

Printing of the component parts

The first step is to print the individual components. For the body parts this is very straight forward as the surface negates the need for supports. The body objects can be printed with the minimum infill for support, though infill of 10% is recommended for rigidity.

Components of the SARS-CoV-2 model, with three different variants of spike proteins
Fig. 1. Components of the SARS-CoV-2 model, with three different variants of spike proteins: with holes for springs (left, gray), with rigid stalks (center, red) and with flexible stalks made from a softer material (right, green).

The spike proteins provide a more challenging print. The spike protein must be printed 26 times to complete the model. To represent the variety of conformations among the proteins in any given moment, we provide spikes in three different tilt angles in both the extended and the retracted state each. For a mixture of spike proteins that reflects a real-life virion reasonably well, we recommend this distribution:

For the model with rigid spikes:

  • 3x 30° extended
  • 4x 30° retracted
  • 5x 40° extended
  • 7x 40° retracted
  • 3x 50° extended
  • 4x 50° retracted

For the model with springs:

  • 11x extended
  • 15x retracted

The springs have to be about 3.2 mm in outer diameter and 18-19 mm in length. We recommend using stainless steel springs. To bend the springs, they are pulled onto several solid wires, which are bent into different spiral shapes. The wires with springs are then placed on a hot plate at 250 °C for 30 minutes. By using this method, different, random spring angles can be realized and the springs can be prevented from bending back into their original position.

We recommend printing the spike protein lying sideways as this results in stronger stalks. It is not too difficult to remove the supports of the stalks without breaking them.

We used FDM printing and ubiquitous poly-lactic acid (PLA), which made the post-processing easier.

A dual extruder printer would be ideal for spike printing as it would allow supports to be printed with water-soluble plastic, speeding up post-processing. In any case, printing individual or at least fewer spikes with greater spacing generally produces nicer objects which are easier to work with at the price of longer printing time.

Post-processing

Regardless of the approach taken for printing, some tidying will typically be needed to get the virion ready for assembly. Removing the supports can be done with a pair of pliers, while the smaller artifacts and issues will need brushing off or sanding. A dental pick can be quite useful.

 

Update: How to make your own 3D printed coronavirus model version 2 13
Fig. 2. Complete printed, painted and assembled SARS-CoV-2 models with rigid spike proteins and springs.

For PLA, we found the best thing to clean and smooth the surfaces (after support removal) is ethyl acetate. While ethyl acetate is readily available in many chemical labs or at a pharmacy, acetone-free nail-polish remover offers a commercially accessible alternative. You should be using safety glasses and accurately fitting (!) gloves when handling ethyl acetate, ventilate the room well and, in case of skin contact, use a skin cream after washing your hands! It dissolves the plastic, breaking down the small extrusion artifacts on the surfaces and can be applied in many ways. We found it best to leave the parts in a sealed ethyl acetate vapor environment, e.g. by putting it in a smaller open vessel into a stainless-steel pot, which should be cleaned carefully afterwards. This technique results in even and clean results, though it will take up to a few days to fully smooth each object. The faster method is to simply submerge the small objects in ethyl acetate for 10-30 seconds, and then remove each object, leaving them to dry out on a surface. For the larger virion parts, the surface can be smoothed by rubbing it down with a cloth damped with ethyl acetate, which was also used to “weld” the two viral hull halves parts together. A small amount was dropped onto the flat surfaces on each section, before the two were pressed together until the plastic fused to become a single object. The seam was then smoothed down using the same process as before.

For acrylonitrile butadiene styrene (ABS), acetone may produce the same results.

Ready for Assembly!

Finally, the 3D model can be assembled. For assembling, the springs are first fixed with superglue in the holes of the body. UV resin is then used for their final fixation. The UV resin also serves as a filling material to completely close the holes. The spikes are attached to the springs in the same way as the springs are attached to the body. If the intention is to paint the model, we recommend assembling the model before starting with the coloring. In this way, the UV resin used to fill the holes can also be painted and a more visually appealing result can be achieved.

We hope that our adventure in 3D printing the coronavirus inspires you to give it a try! The process we described was completed in a little over a week. The printing jobs were completed in just over two days, the cleaning and post-processing took another two days, while the painting was done over the course of a weekend. This article provides a description of our technique and should provide enough detail on how, with the outlined necessary tools, you can create a similar result. The files have been distributed through Thingiverse under a Creative Commons BY-NC license: You may remix, adapt, and build upon this work non-commercially and acknowledge the "Coronavirus Structural Task Force" as original author.

https://www.thingiverse.com/thing:5326932

As with every 3D printed model, there are many different ways this could be tackled and achieved, and we look forward to seeing the many creative ways explored by others in this endeavor. Please do share experiences and results with us, either through the comments Thingiverse or on Twitter (you can tag us @thornlab).

Complete printed, painted and assembled SARS-CoV-2 spring model, with human antibody and rhinovirus at the same scale.
Fig. 3. Complete printed, painted and assembled SARS-CoV-2 spring model, with human antibody (orange) and rhinovirus (blue) at the same scale.

We have also designed a scale model of the human anti-body that binds to the spike protein. This is available alongside the virus model and can be attached to the spike protein as desired.

For a sense of perspective, we have also produced a model of the rhinovirus, which is one of the viruses that cause the common cold, at the same scale. It is available in STL format here: https://www.thingiverse.com/thing:4556845

Authors

We want to emphasize that the writing of this blog entry was a collaboration of a several people:

Dale Tronrud and Thomas Splettstößer worked together to create the STL files for the 3D model. Dale was the person to suggest it first (with Andrea Thorn picking up on the idea). Thomas then selected the experimental models and placed all the parts to form a realistic representation. Dale provided the knowledge about the limitations imposed by the nature of 3D printing and broke up Thomas’ model into printable parts that can be assembled without too much difficulty. He printed and assembled the first virion from this design. The updated model was printed at the facilities of the Physics department at the Universität Hamburg with generous support from PhysNET and Martin Stieben. Yunyun Gao and Philip Wehling refined the model, and Matthias Stäb painted the one shown in the pictures.


Corinna the Corona Cactus

@
Corinna works as an outreach person for all plant-related business and as a mascot. She gathered previous experience in the garden center, and even though she can be a bit spiky, she likes to cuddle and lie in the sun.
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Helen Ginn

Senior Research Scientist @ Diamond Light Source, Oxfordshire, UK
Dr Helen Ginn is a senior research scientist at Diamond Light Source in the UK and a computational methods developer in structural biology. She is currently working on Representation of Protein Entities (RoPE) for structural biologists to interpret subtle conformational changes in dynamic protein systems. She has developed Vagabond for torsion angle-driven model refinement and […]
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Nick Pearce

Assistant Professor @ SciLifeLab DDLS Fellow
Nick obtained his undergraduate degree in Physics from the University of Oxford in 2012, and then his PhD in Systems Approaches to Biomedical Sciences in 2016. He moved to Utrecht in the Netherlands in 2017 to work with Piet Gros, where he obtained an EMBO long-term fellowship and worked on analysing disorder in macromolecular structures. […]
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Molecular Life Sciences M.Sc. Student @ Hamburg University
Mathias is currently doing his Master's degree in Molecular Life Sciences at the University of Hamburg and has been an auxiliary scientist in the Corona Structural Taskforce since March 2022. There he is working on the question of the origin of SARS-CoV-2. His undergraduate research focuses on the development of synthetic molecular mechanisms to regulate […]
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David Briggs

Principal Laboratory Research Scientist @ Francis Crick Institute in London, UK
David Briggs is a Principal Laboratory Research Scientist in the Signalling and Structural Biology lab at the Francis Crick Institute in London, UK. A crystallographer by training, his work focuses on the biophysical and structural characterisation of human extracellular proteins involved in the synapse, which have important ramifications in both psychiatric and neurodegenerative disorders. He […]
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Lisa Schmidt

Web Developer and Illustrator @ Mullana
Lisa Schmidt is a freelance illustrator who studied Multimedia and Communication (BA) in Ansbach, Germany. Her work is focused on visualising topics around science and technology. She joined the Coronavirus Structural Task Force as media designer, where she does web design, 3D rendering for scientific illustrations and outreach work.
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Philip Wehling

Nanosciences M.Sc. Student @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Philip has long had an enthusiasm for biological processes which is paired with an analytical understanding of the world. After having worked for a long time as a registered nurse in various fields, he first studied mathematics and finally nanosciences. During a lecture series in preparation for a bachelor's thesis, he came into contact with […]
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Binisha Karki

Postdoctoral Research Associate @ BioNTech SE
Binisha works as a research associate at BioNTech where she works on the development of COVID-19 vaccine and cancer immunotherapies. She graduated as a Molecular Biology major from Southeastern Louisiana University in May 2019. Post-graduation she worked as a research technician in the Chodera Lab performing biophysical measurements of model protein-ligand systems for computational chemistry […]
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Binisha Karki

Wissenschaftliche Mitarbeiterin @ BioNTech SE
Binisha ist als wissenschaftliche Mitarbeiterin bei BioNTech angestellt und arbeitet an der Entwicklung von Impfstoffen gegen COVID-19 sowie Krebsimmuntherapien. Sie beendete ihr Studium der Molekularbiologie an der Southeastern Louisiana University im Mai 2019. Anschließend arbeitete sie als Forschungstechnikerin im Chodera-Lab, wo sie biophysikalische Messungen an Modellen von Protein-Liganden-Systeme für computerchemische Benchmarks durchführte.
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Hauke Hillen

Assistant Professor at the University Medical Center Göttingen & Group Leader at the MPI for Biophysical Chemistry @ University Medical Center Göttingen
Hauke ist Biochemiker und Strukturbiologe. Mit seinem Forschungsteam untersucht er mittels Röntgenkristallografie und Kryo-Elektronenmikroskopie die Struktur und Funktion von molekularen Maschinen, die für die Genexpression in eukaryotischen Zellen verantwortlich sind. Er interessiert sich dabei besonders dafür wie genetisches Material außerhalb des Zellkerns exprimiert wird, zum Beispiel in menschlichen Mitochondrien oder durch Viren im Zytoplasma.
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Richardson Lab

Richardson Lab @ Duke University, Durham, North Carolina, USA
The long-term goal of the Richardson lab is to contribute to a deeper understanding of the 3D structures of proteins and RNA, including their description, determinants, folding, evolution, and control. Their approaches include structural bioinformatics, macromolecular crystallography, molecular graphics, analysis of structures, and methods development, currently focussed on the improvement of structural accuracy. In this […]
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Holger Theymann

Agile Leadership Coach @ mehr-Freu.de GmbH
Holger keeps websites running. He makes data from scientific databases appear in nice tables. He also has an eye on keeping the sites fast, safe and reliable. His experience as a software developer, systems architect, agile project manager and coach enabled the Task Force to get the whole process well organized and he even taught […]
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Florens Fischer

Biology M.Sc. Student @ Rudolf Virchow Center, Würzburg University
Florens is studying biology (M.Sc.) and worked in the Task Force as a student assistant. He has focused on bioinformatics and supports the work on automation of scripts and structuralization of big data with machine learning. He also supported the team in other areas, such as scientific research.
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Ezika Joshua Onyeka

Public Health M.Sc. student @ Hamburg University of Applied Sciences
Joshua joined Thorn Lab as a student assistant. He is a Public Health practitioner, holds a bachelor's degree in Public Health and is currently enrolled at Hamburg University of Applied Sciences for his MPH. He has helped in implementing some vaccination programmes to improve immunisation coverage and training of immunisation frontline health workers. For the […]
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Katharina Hoffmann

Molecular Biology M.Sc. student @ Institut für Nanostruktur und Festkörperphysik, Universität Hamburg
Katharina worked as a student assistant at Thorn Lab. Normally, she studies molecular biology at the University of Hamburg. In her master's thesis, which was put on hold by Corona, she is working on the interruption of bacterial communication. Since the lockdown, she has been digging around in databases and analyzing sequences. She never thought […]
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Nicole Dörfel

Media Designer @
Nicole Dörfel ensures that we and our work are looking good! She is the illustrator, media designer and the artistic soul of the Task Force. She works her magic both in print and digitally—her focus is general media design. In the Task Force, she is mainly responsible for graphics, photo editing, design of all our […]
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Pairoh Seeliger

Administration Assistant @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Pairoh Seeliger is the admin wizard of the Task Force. She takes care of media requests, handles any logistical issues that come up and makes sure our science doesn’t sound too complicated in our German outreach efforts. She self-describes as "a jack of all trades with a University education in German studies and business administration, […]
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Oliver Kippes

Biochemistry B.Sc. Student @ Rudolf Virchow Center, Würzburg University
Oli is studying biochemistry (B.Sc) and has completed a training as an IT specialist prior to his studies. With the combined knowledge of his studies and training, he helps maintaining the structural database, programs applications for it and supports the team in literature research. In spite of his study, structural biology was still a new […]
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Luise Kandler

Biochemistry B.Sc. Student @ Rudolf-Virchow Center, Würzburg University
Luise is a B.Sc. student in biochemistry at the University of Würzburg and joined the Task Force during the first Corona lockdown. She did her bachelor's thesis with the Thorn Lab, where she learned programming with Python and worked on the implementation of a GUI for our machine learning tool HARUSPEX in Coot. In the […]
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Ferdinand Kirsten

Biochemistry B.Sc. Student @ Rudolf Virchow Center, Würzburg University
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Biochemistry B.Sc. Student @ Rudolf-Virchow Center, Würzburg University
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Erik Nebelung

Nanoscience M.Sc. Student @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Erik is studying nanoscience with a focus on biochemical methods and applications. From August 2020 till January 2021 he pursued his studies at the iNano institute in Aarhus, before starting his master's thesis back in Hamburg. He had his first taste of protein crystallization during his bachelor's thesis work and this sparked his interest in […]
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Toyin Akinselure

Nanoscience M.Sc. Student @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Toyin ist a microbiologist and presently an M.Sc. student in nanoscience with a focus on nanobiology and nanochemistry. She is interested in scientific research especially in protein chemistry and drug discovery. In the previous autumn and winter, she interned with two research projects, one in drug discovery and the other in protein structure. She found […]
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Lea von Soosten

Physics M.Sc. Student @ Institute for Nanostructure and Solid-State Physics, Hamburg University
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Sabrina Stäb

Biotechnology M.Sc. Student @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Sabrina is studying biochemistry (M.Sc.) and works as a research assistant for the Thorn Lab and the CSTF. During her bachelor thesis on "Crystallization and Structure Solution of High-Quality Structures for MAD Experiments", she was able to gain a lot of experience in the field of crystallography and now brings this experience to the project. […]
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Alexander Matthew Payne

Chemical Biology Ph.D. Student @ Chodera Lab, Memorial Sloan Kettering Center for Cancer Research, New York, U.S.
Alex is a Ph.D. student interested in understanding how proteins move! He has recently joined the labs of John Chodera and Richard Hite to work on a joint project involving molecular dynamics and Cryo-EM. His goal is to generate conformational ensembles from Cryo-EM data and simulate the ensemble using massive scale molecular dynamics via Folding@Home. […]
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Maximilian Edich

Bioinformatics Ph.D. Student @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Max studied bioinformatics and genome research in Bielefeld and joined the CSTF as a Ph.D. student in 2021. Previously, his focus was on molecular modeling. Now, he works on the so-called R-factor gap. He already learned what it is like to be part of a young, scientific team as a member of the iGEM contest […]
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Agnel Praveen Joseph

Computational Scientist @ Science and Technology Facilities Council, UK
Dr. Agnel Praveen works as a computational scientist in the CCP-EM team at the Science and Technology Facilities Council, UK. He is interested in approaches to interpret and validate maps and atomic models derived from Cryo-EM data and looks also into computational methods for the interpretation of Cryo-ET data. In collaboration with five other sites […]
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Dale Tronrud

Research Scientist @
Dale Tronrud has both solved protein crystal structures and developed methods and software for the optimization of macromolecular models against X-ray data and known chemical structural information. He has had a long-standing interest in enzyme:inhibitor complexes and photosynthetic proteins, focusing on the Fenna-Matthews-Olson protein. In addition, he has also been involved in the validation and […]
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Sam Horrell

Beamline Scientist @ Diamond Light Source, Oxfordshire, UK
Sam is a structural biologist working on method development around structural biology at Diamond Light Source, in particular for ways of better understanding how enzymes function through the production of structural movies. Sam is working through deposited structures related to SARS-CoV and SARS-CoV-2 with a view to providing the most accurate protein structures possible for […]
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Cameron Fyfe

Postdoctoral Research Associate @ Micalis Institute, INRAE, Paris, France
Cameron is a structural biologist who has worked extensively on proteins from microorganisms. With many years of experience in the pharmaceutical industry and in structural biology research, he joined the Task Force to contribute his skills to improve existing models for drug development. He is currently researching Radical SAM enzymes at INRAE. When not in […]
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Tristan Croll

Postdoctoral Research Associate @ Cambridge Institute for Medical Research, University of Cambridge
Tristan is a specialist in the modelling of atomic structures into low-resolution crystallographic and cryo-EM density, and developer of the model-building package ISOLDE. His focus in the project is on correcting the various errors in geometry and/or chemical identity that tend to occur in less well-resolved regions, with the overall aim of bringing the standards […]
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Gianluca Santoni

Serial Crystallography Data Scientist @ European Synchrotron Radiation Facility, Grenoble, France
Gianluca is an expert in protein crystallography data collection and analysis. After a PhD in structure-based drug design, he has worked as a postdoc on the beamline ID23-1 at the European Synchrotron Radiation Facility (ESRF) and has developed the SSX data analysis software ccCluster. His current interests are the optimization of data collection strategies for […]
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Yunyun Gao

Postdoctoral Research Associate in the AUSPEX Project @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Yunyun is a method developer for strategies of analysing data from biomacromolecules. Before joining the Thorn group, he had been working on SAXS/WAXS of polymers and proteins. He is interested in improving objectivity and reliability of data analysis. Yunyun is currently extending the functionality of AUSPEX. He is the repository manager and AUSPEX handler for […]
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Johannes Kaub

Scientific Coordinator @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Johannes Kaub studied chemistry at RWTH Aachen, with a focus on solid-state physical chemistry, before serving as a scientific employee at the Max Planck Instiute for the Structure and Dynamics of Matter. He supports the Coronavirus Structural Task Force as a scientific coordinator with his organizing ability and his talent for solving problems. Other than […]
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Andrea Thorn

Group Leader @ Institute for Nanostructure and Solid-State Physics, Hamburg University
Andrea is a specialist for crystallography and Cryo-EM structure solution, having contributed to programs like SHELX, ANODE and (a little bit) to PHASER in the past. Her group develops the diffraction diagnostics tool AUSPEX, a neural network for secondary structure annotation of Cryo-EM maps (HARUSPEX) and enables other scientists to solve problem structures. Andrea is […]
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