Volumetric scanning of biological cells

Cells are micrometers in size. Macromolecules that compose cells (nucleic acids, proteins, and lipids) are nanometers in size. These components move around within cells over milliseconds time scales. Mammalian cells contain diverse organelles; even comparatively simple bacteria have complex and biologically important internal structure.

Currently, what are the best methods to volumetrically image cells and the dynamic processes in which they participate or within them? What are the relative advantages and disadvantages of these methods? What physical limits constrain the spatiotemporal resolution of nanoscale volumetric scanning methods?

  min spatial resolution (m) key physics
nuclear magnetic resonance (NMR) and optical NMR 5x10-9 interaction of spins, magnetic field
near-field confocal optical spectroscopy (NCOS) 2x10-8 evanescent waves, fiber optics
nanofocus computed tomography (nanoCT) 4x10-8 Fresnel lenses
optical coherence tomography (OCT) 2x10-6 Michaelson interference, femtosecond lasers
magnetic induction tomography (MIT) 1x10-3 electromagnetic boundary value problem


This file gives some citations and derivations of these quantities.