Table 1: Mobility parameters obtained for different tracer molecules in vitro and in the nucleus of living cells.

From: Retrieving the intracellular topology from multi-scale protein mobility mapping in living cells

 D (μm2 s1)
msFCCS in vitro
 TetraSpeck beads (0.1 μm diameter)4.4±0.1*
 QDot 525 streptavidin conjugate31±1*
msFCCS in living cells (nucleus)
FRAP in living cells (nucleus)
  1. FRAP, fluorescence recovery after photobleaching; GFP, green fluorescent protein; msFCCS, multi-scale fluorescence cross-correlation spectroscopy; RFP, red fluorescent protein.
  2. Data were either obtained by msFCCS or FRAP with radial profile analysis. The results for TetraSpeck beads in vitro are in excellent agreement with the value D=(4.4±0.7) μm2 s−1 previously determined by dual-focus FCS and dynamic light scattering69. According to the measured diffusion coefficient of QDots, a hydrodynamic radius of rH=(7.8±0.3) nm was calculated that matches the specification value of (8.8±1.3) nm given by the manufacturer (Invitrogen). msFCCS results in living cells agreed very well with FRAP experiments on the same length scale.
  3. *Diffusion constants obtained by auto-correlation analysis are reported, since results were independent on time and length scale.
  4. Diffusion constants for msFCCS analysis with an effective distance of deff=1.2 μm.
  5. FRAP results for a bleach circle radius of wb≈1.3 μm.
  6. §An immobile fraction of (1±1) % was found on the minute time scale.
  7. An immobile fraction of (6±1) % was found on the minute time scale.