Proc. Natl Acad. Sci. USA 109, 13978–13983 (2012)

Imaging membranes in live cells with nanoscale resolution helps reveal the structural dynamics of organelles, such as mitochondria, the endoplasmic reticulum and lysosomes. Now, by performing stochastic optical reconstruction microscopy and exploiting small-molecule probes that have high probe densities and which directly bind to membrane structures, Sang-Hee Shim and colleagues from the USA and China have demonstrated dynamic imaging of specific membrane structures in living cells. A 30–60-nm spatial resolution at temporal resolutions down to 1–2 s was achieved. The researchers identified the photoswitching capabilities of eight small-molecule probes commonly used for labelling the plasma membrane, mitochondria, the endoplasmic reticulum or lysosomes and showed that the different spectral properties of the probes allow for multicolour imaging of mitochondria and the endoplasmic reticulum.