Enhanced diffusion in active intracellular transport

Phys Rev Lett. 2000 Dec 25;85(26 Pt 1):5655-8. doi: 10.1103/PhysRevLett.85.5655.


We show that within a living eukaryotic cell, mean square displacement of an engulfed microsphere shows enhanced diffusion scaling as t(3/2) at short times, with a clear crossover to subdiffusive or ordinary diffusion scaling at longer times. The motion, observed nearby the nucleus, is due to interactions with microtubule-associated motor proteins rather than thermal Brownian motion. We propose that time-dependent friction introduced by the intracellular polymer networks leads to sub-ballistic motion, analogous to subdiffusion observed in passive networks of semiflexible biopolymers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Biological Transport, Active
  • Cells, Cultured
  • Diffusion
  • Fibroblasts / metabolism*
  • Fibroblasts / ultrastructure
  • Fluorescent Antibody Technique
  • Microspheres
  • Molecular Motor Proteins / physiology
  • Polystyrenes / metabolism
  • Rheology


  • Molecular Motor Proteins
  • Polystyrenes