We can now compare electron density and electron intensity profiles obtained from SAXS, cryo-ET and SPA (Figure ). A quantitative analysis using feature positions was carried out to compare these profiles directly: peak-to-peak measurements were taken from all electron profiles to determine whether the data acquired in the SAXS, cryo-ET, FFT of cryo-ET images and SPA correspond to the same structure. the electron profiles resulting from c) FFT analysis of the cryo-ET images and d) SPA. In the thin population of 50 mol% PBd22-PEO14 vesicles there is also excellent correspondence in peak-to-peak distances between the e) SAXS electron density profile and the f) cryo-ET electron intensity profile, as well as electron profiles resulting from g) FFT analysis of the cryo-ET images and h) SPA. Although for the thick 50 mol% PBd22-PEO14 membranes, the i) SAXS electron density profiles do not correspond with j) cryo-ET electron intensity profiles. However, the k) FFT analysis of the cryo-ET images results in a profile that has excellent correspondence to i). Further analysis with l) SPA gives a result that combines some of the features seen in both SAXS and cryo-ET (i&j) profiles, including a higher density peak in the hydrophobic core region indicated by the green circle. Like thick 50 PBd22-PEO14 membranes, 100 mol% PBd22-PEO14 membrane m) SAXS electron density profiles do not correspond with n) cryo-ET electron intensity profiles. However, o) FFT analysis of the cryo-ET images results in a profile that has excellent correspondence to m). Further analysis with p) SPA gives a result that combines the features seen in both SAXS and cryo-ET (m&n) profiles including a higher density peak in the hydrophobic core region indicated by the green circle.