Current Lab Members

Sandra Scharaw

Group Leader

Sandra Scharaw

Group Leader
scharaw@mpi-cbg.de
+49 351 210-2634

Helin Giris Timurtas

Predoc

Helin Giris Timurtas

Predoc
giris@mpi-cbg.de

David Grommisch

Postdoc

David Grommisch

Postdoc
david.grommisch@mpi-cbg.de
+49 351 210-2636

Musashi Koyama

Musashi Koyama


koyama@mpi-cbg.de

Joon Ho Lee

TA

Joon Ho Lee

TA
jlee@mpi-cbg.de
+49 351 210-2635

Bram J. van Rijnsoever

Master student

Bram J. van Rijnsoever

Master student
vanrijns@mpi-cbg.de

Jun Yang

Postdoc

Jun Yang

Postdoc
jyang@mpi-cbg.de

Helin Giris Timurtas

M.Sc. Double-degree in International Master’s Program in Innovative Medicine, Heidelberg University, Germany + Uppsala Universitet, Sweden
B.Sc. Molecular Biology and Genetics, Izmir Institute of Technology, Izmir, Türkiye

During my bachelor’s studies, I rotated through different scientific hubs, where I exposed myself to a variety of techniques and perspectives to better understand biology from multiple angles. Soon after, although I majored in molecular biology, I became increasingly interested in cellular-level dynamics in health and disease. At the same time, I focused on learning diverse methods, including advanced imaging techniques, iPSC culture, and the production of lab-on-a-chip devices.

For my PhD, I want to specifically explore the subcellular and cellular dynamics of the intestinal crypt niche. By utilising advanced imaging methods, I aim to investigate the organisation of endomembrane organelles within the intestinal stem cell niche. Ultimately, I believe that uncovering the importance of endomembrane organelle organisation will deepen our understanding of the dynamics of ageing.
Outside the lab or the microscopy room, you will probably find me at the gym, where I enjoy lifting weights. Besides that, I like reading novels, watching movies, and spending time with family and friends.

David Grommisch

Postdoc (since 2024)
PhD (Medical Science, Karolinska Institutet, Sweden - Group of Dr. Maria Genander)
M.Sc. (Biomedicine, Karolinska Institutet, Sweden)
B.Sc. (Molecular Biotechnology, Heidelberg University)

How cells communicate and interact to form and maintain complex tissues fascinates me. In my PhD I focused on epithelial progenitor cell behaviour of the skin and oesophagus and how their cellular environment regulates cell fate decisions. I focused on in vivo lineage tracing, organoid models, and next generation sequencing techniques.
As a Postdoc I want to delve deeper into the cellular biology of intercellular communication by visualising cell-cell communication in intestinal organoids. I hope this helps me to understand how altered intercellular communication contributes to stem cell dysfunction with age.

Outside the lab I enjoy doing sports, cooking (& eating!), reading, and visiting and spending time with friends. I enjoy arts and music and wish I’d take more time to play guitar again. Maybe in later years I wish I’d worked more on investigating ageing while I play the guitar…

Joon Ho Lee

I started my scientific journey as a biochemistry undergraduate at University of Wisconsin – Madison. After enduring some heavy snowstorms in winters and enjoying my time next to Lake Mendota in summers, I graduated from Madison and started my master’s program in chemistry at Yonsei University in Seoul.

After completing my master’s degree, I relocated to Dresden in 2020 (bad year to travel, terrible year to move to a new country…oof). Despite the initial challenges, I have been enjoying my time living and working in Dresden and in Germany. Since I started to work in Dresden, I have mainly gained experience with organoids, African clawed frog (xenopus laevis), various mouse work to name a few.

I have been part of MPI-CBG since 2023 and I am very happy to be working at Sandra Scharaw’s group as a TA and helping the group whenever possible!

Outside of the lab, I like to spend my time cooking something new, visiting restaurants and cafés, traveling in and out of Europe, and practicing clarinet (Squidward style).

Bram J. van Rijnsoever

Master's Student

M.Sc., Molecular and Cellular Life Sciences, Utrecht University, The Netherlands
B.Sc., Biology & Medical Laboratory Research (Life Sciences) HU University of Applied Sciences Utrecht, The Netherlands

I performed my Major Research Project in the research group of Prof. Dr. Mike Boxem, at Utrecht University. There, I contributed to the understanding of the molecular mechanisms involved in epithelial cell polarity, using the model organism Caenorhabditis elegans.

After completing the internship, I wanted to broaden my research skills and my interest was drawn in particular by organoid research, as I did not yet have the chance to work with a 3D in vitro system. This combined with my desire to go abroad, brought me to the research group of Dr. Sandra Scharaw, where I am currently performing my Minor Research Project.

In this project, my goal is to establish Auxin-Induced Degradation in mouse small intestinal organoids. This versatile system allows spatio-temporal control over protein degradation, enabling us to investigate the molecular mechanisms of Golgi organization.

Outside the lab, I enjoy making the most of my free time. When I feel active, I like running along the Elbe, mountain biking in the Dresdner Heide, or exploring the city of Dresden. On quieter days, I enjoy reading, playing video games or spending time with friends.

Jun Yang, PhD

Ph.D. Chemical and Biomolecular Engineering, University of Notre Dame, USA – Group of Dr. Pinar Zorlutuna
M.Sc. Chemical and Biomolecular Engineering, Johns Hopkins University, USA
B.Sc. Environmental Engineering, South China Normal University, China

I started my scientific journey in bioengineering, where I explored drug delivery and tissue engineering in cancer, and became fascinated by how the microenvironment shapes cell behaviors in health and disease. During my PhD, I focused on how the aging tumor microenvironment influences breast cancer progression, using engineered 3D models and extracellular vesicle analysis to study cell–matrix interactions and age-specific drug responses.

As a postdoc in Sandra’s group, I am excited to expand my work on cell–cell and cell–matrix communication, particularly in the context of stem cell and aging biology. I hope to integrate my background in bioengineering with the lab’s expertise in cell biology to better understand how aging alters tissue organization and stem cell functions.
Outside the lab, I share my free time with my cat Yuumi. We read, knit, watch movies and sports, listen to music and true crime podcasts while we play fetch and cuddle.