FIGURE 1:

Molecule counting in single-molecule localization microscopy. From the time-ordered series of total internal reflection images used to create the SMLM image (left; scale bar, 500 nm), one determines fluorescence intensity traces at particular spots (boxes) as a function of time. The number n of blinking events in these traces is counted (middle). The number of colocalized molecules is then determined from the frequency distribution c(n) of the number n of blinking events (right) by comparison to predictions for different oligomerization states (lines).