Fig. 1: LAURDAN spectral phasors allow measurement of changes in membrane packing and hydration.
a LAURDAN spectra reconstituted from hyperspectral imaging of GUVs made of three different lipids. Data are represented as the mean (dots and lines) ± SD (shadowed contour), n = 5 vesicles per condition. b Spectral phasor plot for hyperspectral images of DOPC, DLPC, and DPPC GUVs containing 0.5 mol% LAURDAN at (23 ± 1)°C. The plot corresponds to at least five images per condition. Increasing the chain length results in an increase in packing evidenced by the shift of the pixel clouds in a clockwise manner. The pixel clouds are colored according to the pixel density, increasing from blue to red. c Pixel distribution histograms along the linear trajectory (white dotted line in b), showing the fluidity fraction for the different lipid membranes. Data are represented as the mean (dots and lines) ± SD (shaded area), n = 5 independent experiments per condition. d Representative confocal microscopy images of GUVs of the indicated lipids (upper panel). Using circular cursors to select the pixel clouds in (b), the corresponding pixels are colored in the images, as shown in the lower panel. Scale bars: 5 µm. e Center of mass of the histograms shown in (c). Individual data points are shown for each membrane composition. The lines indicate the mean value ± SD (n = 5). The statistical analysis was performed with One-way ANOVA and Tukey post test analysis (p < 0.0001, **** | p < 0.001, *** | p < 0.01, ** | p < 0.05, * | ns non-significant). Source data are provided as a Source Data file.
