The genetic material of most organisms is carried by DNA, a complex organic molecule. DNA is very long—for humans, the molecule is estimated to be about 2 m in length. In cells, DNA occurs in a densely packed form, with strands of the molecule coiled up in a complicated but efficient space-filling way. A key role in DNA's compactification is played by histones, structural-support proteins around which a part of a DNA molecule can wrap. The DNA-histone wrapping process is reversible—the two molecules can unwrap and rewrap—but little is known about the mechanisms at play. Now, by applying high-speed atomic-force microscopy (HS-AFM), Richard Wong and colleagues from Kanazawa University (NanoLSI WPI) provide valuable insights into the spatiotemporal dynamics of DNA-histone interactions.