Experiencing Science in the Lab: DKTK Researchers Turn an ISH Placement into an Ambassador Activity

The International Summer Science School Heidelberg (ISH), organized by the City of Heidelberg and research institutions in Heidelberg, is a four-week programme for students aged 16 to 20, who are interested in natural sciences and would like to get a practical insight into the laboratories of renowned research institutes. It combines an introduction to research with international exchange among young people from Heidelberg and its partner cities and organisations. In 2026, the research internships took place from 20 July to 5 August.
Sia (USA) and Gil (Israel) joined Dr. Kendra Maaß’s “Prevention and Liquid Biopsies” research group. Based at the German Cancer Research Center (DKFZ), the University Clinic Heidelberg (UKHD), and the Hopp Children’s Cancer Center Heidelberg (KiTZ), the group develops and investigates liquid biopsy approaches for paediatric oncology. 
For Sia, Heidelberg’s close links between laboratory research and clinical medicine were a particular draw: “I was excited by the collaborative environment, where scientists and clinicians work together to move discoveries from the laboratory towards patient care.”

Reading molecular traces in body fluids

Liquid biopsies obtain molecular information from body fluids such as blood plasma or cerebrospinal fluid. One important source of this information is cell-free DNA, or cfDNA: short fragments of DNA released through normal cell turnover and other biological processes. In people with cancer, some of these fragments may originate from tumour cells. 
In paediatric oncology, liquid biopsy technologies offer a comparatively minimally invasive route to molecular information that may support research into diagnosis, risk stratification and disease monitoring. The Maaß group works to refine these approaches and explore how they can complement established diagnostic procedures.
During the project, entitled “cfDNA Everywhere – Exploring cfDNA in Everyday Conditions”, Sia and Gil gained practical experience with key laboratory steps, including plasma processing, cfDNA isolation and the quantitative and qualitative assessment of samples. 

In an effort to assess how robust liquid biopsies are under different pre-analytical conditions, Gil and Sia designed a series of experiments together with the researchers from the Maaß lab. Relevant confounders such as UV light, heat and sample agitation were identified and compared with samples handled under optimal conditions. This is particularly relevant for settings in which controlled transport and storage are not always feasible. Testing the effect of these conditions could therefore help to make liquid biopsies more accessible worldwide. 

Experiencing research first-hand

Beyond learning individual techniques, the placement introduced the participants to research as an open and iterative process. “What excites me most about working in a lab is seeing science happen in real time,” Gil said. “You’re not just learning existing knowledge; you’re helping create new knowledge.”
Sia was similarly drawn to the uncertainty inherent in experimentation: “Every experiment begins with a hypothesis, but there’s no guarantee the results will match your expectations - and that’s what makes research so exciting.”
The experience also connected with the participants’ individual career interests. Sia hopes to combine molecular oncology, cancer genetics and patient-centred research. Gil is particularly interested in molecular biology, genetics, cell biology and biochemistry.

Promoting up-and-coming scientists

By offering this research internship, Dr. Kendra Maaß’s group contributed to the outreach objectives of the DKTK Ambassador Programme, launched by the German Cancer Consortium (DKTK) in 2025. With close guidance from Maaß lab’s scientists Florian Iser and Samuel Zabel, the two interns gained hands-on experience in laboratory research while exploring how laboratory findings can ultimately translate into benefits for patients. This provided an exciting glimpse into modern translational cancer research, the close connection between scientific discovery and clinical application, and careers in science.

More about the DKTK Ambassador Programme