Supplementary Figure 6: EGFR SOMAmer versus antibody linkage error comparison.

(a) DNA-PAINT overview image of SOMAmer-stained EGFR proteins. (b) DNA-PAINT overview image of primary- and DNA-conjugated-secondary-stained EGFR proteins. (c) ~ 20,000 single receptor molecules labeled using SOMAmers aligned by their center of mass (left). 1D histogram of localizations yields a combined labeling and imaging precision of 4.4 nm (right). (d) ~ 30,000 single receptor molecules labeled using antibodies aligned by their center of mass (left). 1D histogram of localizations yields a combined labeling and imaging precision of 9.4 nm. The difference between SOMAmer- and antibody-based labeling stems almost exclusively from the increased linkage error of the primary/secondary antibody sandwich, as we localize single molecules in both experiments with ~ 4 nm precision. This demonstrates that SOMAmer labels in this case are not the precision-limiting factor when imaging single EGFR protein molecules, while antibody labeling broadens the true protein localization roughly two-fold.