Prof. Viki Allan
Mr. Daniel Han
Division of Molecular & Cellular Function, The University of Manchester
Prof. Viki Allan is the leader of a group at the University of Manchester that studies cell dynamics, with a particular focus on intracellular transport and the endocytic pathway. Membrane organelles move around cells along microtubule tracks, driven by proteins such as kinesin and cytoplasmic dynein, and this movement of material within a cell is vital for cell function. Prof Allan and the team are studying these intracellular structures through imaging of living cells.
There are a number of challenges involved in this imaging research, mainly due to the intracellular cargo and transport networks being very small, having a dim signal, and moving rapidly.
Many intracellular membrane organelles are smaller than the diffraction limit for imaging (~200 nm) and can be difficult to resolve. These samples are labeled with low levels of GFP in order to avoid altering organelle behavior, meaning that they don’t exhibit a bright signal, making detector sensitivity a must. In addition, these transport structures can move at a rate of 8 µm/s (typically ~2-5µm/s), which makes them a challenge to track when imaging at high magnification. In order to track these objects successfully, a large field of view and a high framerate camera would be necessary.
Using a camera with the right pixel size could satisfy the Nyquist criterion and achieve a high resolution at a lower field of view, combined with high sensitivity and high speeds. The choice of camera is important when facing these challenges.
With [the Prime 95B] we can go at faster framerates than with an EMCCD, and we can use full frame to see as much of the cell as possible.
Han D., Korabel N., Chen R., Johnston M., Gavrilova A., Allan V.J., Fedotov S., Waigh T.A. (2020) Deciphering anomalous heterogeneous intracellular transport with neural networks, eLife 9:e52224, https://doi.org/10.7554/eLife.52224