In life sciences, the ability to measure the distribution of biomolecules inside a cell in situ is an important investigative goal. Among a variety of techniques, scientists have used magnetic imaging (MI) based on the nitrogen vacancy center (NV) in diamonds as a powerful tool in biomolecular research. However, nanoscale imaging of intracellular proteins has remained a challenge thus far. In a recent study now published in Science Advances, Pengfei Wang and colleagues at the interdisciplinary departments of physics, biomacromolecules, quantum information and life sciences in China, used ferritin proteins to demonstrate the MI realization of endogenous proteins in a single cell, using the nitrogen-vacancy (NV) center as the sensor. They imaged intracellular ferritins and ferritin-containing organelles using MI and correlative electron microscopy to pave the way for nanoscale magnetic imaging (MI) of intracellular proteins.