IMB ( www.imb.de ) is a research institute on the campus of the Johannes Gutenberg University in Mainz, Germany. It is generously funded by the Boehringer Ingelheim Foundation and the state of Rhineland-Palatinate. Our research focuses on the biology of the cell nucleus and ranges from the molecular level to systems and computational approaches. Researchers at IMB are supported by strong core facilities that offer state-of-the-art services in bioinformatics, cytometry, genomics, microscopy, proteomics, and protein production. Transcription is a fundamental process that must be precisely regulated for cells to function and for organisms to develop. Pioneer transcription factors (PTFs) play a special role by opening chromatin and activating gene expression programs that define cell identity. Recent studies show that many PTFs form liquid-like condensates, which are key to regulating this process. Our group (www.wittmannlab.com) investigates how such condensates form, what proteins they contain, and how they influence chromatin. Using recombinant proteins and advanced single-molecule assays, we reconstitute these processes in vitro to uncover the molecular principles of transcriptional programming. The project: “Transcription Factor Condensation in Chromatin Opening” This project explores how PTFs use biomolecular condensation to remodel chromatin structure. While PTFs are known to access DNA within compacted chromatin, the role of their condensates in facilitating chromatin opening remains unclear. To address this, chromatin is reconstituted in vitro using fluorescently labeled histones and defined DNA templates, and its interaction with PTFs is studied using single-molecule techniques. These include optical tweezers to detect nucleosome unwrapping through force spectroscopy, and the carpet assay to visualize condensate formation on surface immobilized chromatin via TIRF microscopy. Together, these approaches allow to dissect how PTF condensation influences chromatin accessibility at the single-molecule level. Experience in protein purification and fluorescence microscopy is of advantage but not mandatory, you will receive training in the respective techniques in our laboratory. Besides standard molecular biology techniques (SDS-PAGE, molecular cloning, etc.) you will apply some of the following specialized methods during the course of the proposed project: Purification of Yamanaka Factors and other disordered transcription factors (Affinity- and Size Exclusion Chromatography) Reconstitution of nucleosomes and chromatin fibers from purified components Biochemical characterization of chromatin fibers (MNase-Assays, EMSA) Single-Molecule imaging of transcription factor condensates on DNA and chromatin fibers (TIRF microscopy, confocal microscopy) Single-Molecule force spectroscopy (optical tweezers) Requirements Excitement about Condensation and/or Chromatin Biology and Single-Molecule Imaging Very good oral and written communication skills in English Good organizational skills and high sense of responsibility Motivation and team spirit Experience with good scientific practices and careful work in the laboratory As a master student at IMB, you will be part of our Internship Programme (www.imb.de/internships). We offer a stimulating, diverse and international research environment, with a pleasant working atmosphere and the opportunity to perform state-of-the-art experiments. The institute is modern, well-equipped and centrally located with good public transport links and parking. Our offer includes Advanced training opportunities Team events Flexible working hours What else you need to know Starting Date: flexible, between October 2025 and January 2026 Duration: 6 months Deadline: 30.09.2025