Contact between mitochondria and endoplasmic reticulum

The subcellular structures called mitochondria (green), which a cell uses to make energy, interact with the endoplasmic reticulum (magenta), a network of ducts inside the cell, in this high-resolution video. Credit: Y. Guo et al./Cell

Cell biology

Crystal-clear movies show the bustling activity inside a cell

Imaging technique gives researchers a peek at a cell’s humming internal machinery.

High-resolution movies have captured a cell’s tiny inner structures going about their business.

Cells contain components called organelles, which perform a variety of roles and work together to help cells function. But it is tricky to observe their interactions with existing imaging techniques.

To get a better view, Dong Li at the Chinese Academy of Sciences in Beijing and his colleagues labelled organelles with fluorescent markers. They then shone a light just far enough into the cell to light up the structures without illuminating the background. The team’s videos of events inside the cell have a resolution as high as 97 nanometres and are composed of as many as 266 frames per second.

One such video shows how mitochondria — the cell’s power generators — tend to divide at locations where they make contact with an intracellular membrane system called the endoplasmic reticulum.

The authors say that, with further development, their technique might enable production of super-resolution 3D images of organelles’ dynamics.