Fig. 4

Multivariate and machine learning analysis of Raman spectra from fixed organoids facilitates separation of untreated and EGF- and FGF2-treated organoids. A–I Multivariate SVD analysis of data from Fig. 3 with control versus FGF2 (A–C), control versus EGF (D–F), and EGF versus FGF2 (G–I). For each comparison, there is an SVD plot where each dot represents a single spectrum, with clustering of similar spectra (A, D, G). A line in each SVD plot is placed perpendicular and equidistant to the mean of each treatment to separate the treatments in an unbiased manner. The distribution of the spectra in each region is plotted in B, E, and H, while the SVD components producing the distribution are plotted in C, F, and I. Select regions of interest within the component graphs are highlighted in yellow (n = 50 separate spectra collected from a minimum of three independent organoids, representative experiment). J Classification accuracy of machine learning (RSVM) on fixed Raman organoid mixed datasets, as indicated, and displayed as a violin plot (120 spectra per comparison; standard deviation less than 0.10 for all comparisons)