Figure 1: From FCS to DODS.

FCS and DODS measurements on the distal membrane of a GUV. (a-c) z-axial scans with measured intensity, I, (grey dots) and Gaussian fit (grey line) in kilo counts per second (kcps). ξ is the correlation amplitude of the recorded ACF (coloured dots); (d–g) sketch of the membrane (dark blue sheet) with different fluorophore concentration (yellow dots) in the confocal volume; (h–k) ACF measured at indicated point (central point, CP, or inflection point, IP). (a,d,h) standard FCS with tense, that is non-fluctuating membrane, low fluorophore concentration (ξ exhibits a single peak at CP, and ACF is recorded at the intensity peak CP); (b,e,i) suppression of FCS signal with high fluorophore concentration in tense membrane (ξ is low throughout the scan and ACF exhibits a very low signal at CP); (c,f,j) and (g,k)) DODS with deflated that is fluctuating membrane and high fluorophore concentration (ξ has peaks at the IPs of I(z), the ACF recorded at CP exhibits a low signal (f,j), while the signal at IP is high (g,k)).