Kirstine Berg-Sørensen is associate professor in biological physics at the Department of Health Technology, Technical University of Denmark. She was educated at the University of Aarhus, with a 1-year stay with Jean Dalibard at the Ecole Normale Superieure in Paris, France, during her Ph.D. studies. In her Ph.D. work and first postdoctoral experiences she concentrated on quantum mechanical and semiclassical models for laser cooling and the physics of cold atoms, as a postdoctoral fellow with Lene Hau, Rowland Institute for Science, Cambridge, MA, USA, and Chris Pethick, NORDITA, Copenhagen, Denmark. Later, her research activities became focused on the physics of biological systems; triggered by some of the first reports on the use of optical tweezers in single molecule biophysics following which she secured funding to construct the first optical tweezers in Denmark, at the University of Copenhagen. Her own research in biological physics has been concentrated on simple models and precise data analysis for single molecule experiments with optical tweezers, followed by experiments using optical stretchers at the Technical University of Denmark. In her current work, she combines quantum bio-sensing by means of NV-centers in diamond with optical trapping. In particular, optical trapping of intracellular nanodiamonds with the goal to correlate NV-center sensing modalities with microrheology and mechanobiology.