Fig. 3

FGF2-treated organoids have a Raman signature that is distinct from EGF-treated or untreated organoids. A Representative brightfield images of fixed organoids on the Raman confocal stage; the cell-dense regions (dark brown) are easily distinguished from the Matrigel-dominant area (scale bar, 200 µm). B Average Raman spectra for cell-dense regions of control and EGF- and FGF2-treated organoids, with error bars representing the 95% confidence interval. C–K Quantification of select peak intensities in the spectral dataset based on the ability to differentiate one or more treatments (n = 50 separate spectra collected from a minimum of three independent organoids; representative experiment * asterisk indicates significance with p < 0.05; statistical summary in Additional file 1: Table S5)