Extended Data Fig. 2: Non-specific binding in ZMWs.
From: cAMP binding to closed pacemaker ion channels is non-cooperative
a, Bright field image of ZMW array on single-molecule imaging set-up featuring a 512 × 512 pixel EMCCD and a 100× objective. Each white dot (about 1,600 per field of view) is a ZMW. b, c, Test of specific binding of eGFP-tagged HCN2SM to ZMWs (b) and of fcAMP (c) to HCN2SM in ZMWs. For b and c, all images shown are averaged over the first 10 frames (1 s) and background subtracted for visualization. Brightness and contrast were adjusted for clarity. d, Representative and randomly selected fluorescence trajectories of empty (no HCN) and passivated ZMWs with 1,000 nM fcAMP fit with DISC (black). The first 50 frames (grey) were removed from analysis.
