Fig. 3
From: An integrative Raman microscopy-based workflow for rapid in situ analysis of microalgal lipid bodies
Calibration curves for quantitative assessment of extracted micro-algal lipids. Integrated peak intensities obtained from Raman spectra of fatty acid standards were used to calculate the intensity ratio I 1650/I 1440. a shows the linear variation of intensity ratio with the degree of unsaturation (i.e., C=C bonds), b shows the linear variation of intensity ratio with NC=C/NCH2 (i.e., ratio of the number of C=C bonds with the number of –CH2– units), and c shows the sigmoidal variation of intensity ratio with melting points of fatty acid standards. Black line (1) represents curve-fit to the data obtained using 532 nm excitation and blue line (2) represents curve-fit to the data obtained using 785 nm excitation. Results of the ratiometric analysis of lipids expressed in C. reinhardtii (CC-503) using the two lasers are shown by red and green circles on the respective calibration curves