FIGURE 4.
Restricted diffusion. (A) Centroid distributions of a bead displaying restricted diffusion. The flow chamber contained all the constituents necessary to support poly(U) programmed poly(Phe) synthesis by the ribosomes immobilized on the surface. The distribution was measured at 17, 54, and 95 min after sealing the chamber, as indicated by the magenta, orange, and black symbols, respectively. (B) For the same bead, Drms is plotted as a function of time (green circles); Drms of an immobile bead present in the same microscopic field is also plotted (red squares), as well as the Drms of a bead in a different field, displaying a large range of diffusion throughout the time of the experiment (blue triangles). (C) TPM data pooled from six beads displaying a reduction of Drms with time. The recordings from different beads were aligned by shifting each set of data to the origin at the first measurement. Each set of data is represented by a different symbol. The line is a linear regression through the pooled data, yielding a slope of −2.8 ± 0.3 (standard error) nm/min; r2 = 0.73.