Fig. 1.

Univariate nanoclustering analysis quantifies the lateral spatial distribution of a single population of gold nanoparticles on the intact plasma membrane sheets. A An intact PM sheet of kidney cells ectopically expressing GFP-K-Ras was attached to an EM grid, fixed and immunolabeled with 4.5-nm gold nanoparticles. Gold distribution on the intact PM sheet was imaged using transmission EM at 100,000× magnification. B x and y-coordinates of the gold particles were assigned using ImageJ and were used to calculate the spatial distribution. Blue dots indicate monomers; yellow dots indicate dimers; orange dots indicate trimers; red dots indicate higher ordered oligomers. C The extent of nanoclustering, L(r) − r, was plotted against the length scale, r, in nanometer. L(r) − r values above the 99% confidence interval (99% CI) indicate statistically meaningful clustering