Figure 1
From: 'Single molecule': theory and experiments, an introduction
Brownian motion and FRET. (A) Brownian motion of a latex particle, 2 μm in diameter; time between frames 4 s; the movement is in 3-dimensions; in particular, panels 4 and 7-10 show that the bead does not remain on the same focal plane; the apparent shape of the bead provides the measure for the motion along the z-axis; (B) Starting point (left) and superposition of images over 44 s; (C) Schematics of the Brownian motion of a particle; (D) A flexible molecule experiences the same type of fluctuations, which can be revealed by FRET between a donor (D) and acceptor (A) pair of fluorophores; (E) The corresponding signal of fluorescence is shown as a function of time.