Fig. 2: Statistical analysis of droplet fluorescence microscopy images makes it possible to track the condensation of nanotubes in a population of droplets.
From: Dynamic self-assembly of compartmentalized DNA nanotubes
a The two-tile nanotube design requires both tile A and B (shown in green and gray), each with sticky-ends complementary to those of the other tile, for nucleation and polymerization of nanotubes. The tiles are annealed in vitro separately and mixed immediately before encapsulation. b Temporal sequence of representative fluorescence microscopy images of droplets encapsulating the two-tile nanotubes at room temperature (each tile at 100 nM). c We examine the distribution of pixel brightness across a single droplet over time. As nanotubes assemble, a change in the shape of the distribution also occurs. Each plot shows the histogram of pixel brightness within the droplet of interest at the associated time. Data for this illustrative figure were extracted by hand using ImageJ. d Skewness is a measure of the asymmetry of the distribution of a random variable about its mean. e Kurtosis is a measure of the “tailedness” of the distribution of a random variable. f The skewness and kurtosis values (represented as purple dots and orange diamonds, respectively) increase as nanotubes start growing and becoming more apparent over time inside the droplet. This graph represents a single droplet only. Source data for this figure is provided as a source data file. Scale bar: 20 μm.
