Fig. 5: Quantification of in vivo spectra revealed the preserved physical properties in non-LD regions.
From: Raman microscopy-based quantification of the physical properties of intracellular lipids
a, b Raman hyperspectral data in Fig. 3 were converted into PC18:1(d0)/PC16:0(d62) ratio images. Representative results of the fitting at the same pixel as Fig. 3 (represented by white crosshairs 1 and 2) are displayed in the graphs on the right, with the calculated PC18:1(d0)/PC16:0(d62) ratio values. The background spectra from the same pixel as Fig. 3 (represented by white crosshair 3) were used for calculation. c, d PC18:1(d0)/PC16:0(d62) ratio images in (a) and (b) were further converted into gauche/trans ratio images. e HeLa cells treated with a total of 130 μM C16:0. The representative result of the fitting at the pixel represented by red and white crosshair 2 is displayed in the bottom graph, with the calculated PC18:1(d0)/PC16:0(d62) ratio value. The background spectra from the pixel represented by red and white crosshair 3 were used for calculation. The PC18:1(d0)/PC16:0(d62) and gauche/trans ratio images are displayed with the same color scaling as (a), (b), (c), and (d). The C–D and C–H vibration images and the bright field image are displayed to show the distribution patterns of C16:0(d31) and the shape of the cell. In the graph of (a), (b), and (e), measured spectra are indicated with black lines, and estimated C16:0(d31) spectra, background spectra, baseline drift, and their summation are displayed with solid-colored lines, solid gray lines, dashed gray straight lines, and dashed colored lines, respectively. f, g Comparison of quantified PC18:1(d0)/PC16:0(d62) and gauche/trans ratios between LD and non-LD regions. The average ratio of LD and non-LD regions were calculated for five to seven cells and plotted. Red horizontal dashed lines indicate the average value for each condition. Conditions are ordered according to the average PC18:1(d0)/PC16:0(d62) ratio value in the LD region. h Quantification of the ratio of LD area to the sum of LD and non-LD area. These ratio values were calculated using the same data set as (f) and (g), and average values and each data point are represented with gray bar-graphs and black dots, respectively. Scale bar indicates 10 μm. Source data are available in Supplementary Data 2.
