Extended Data Fig. 7: Comparison of topical dyes applied to fresh mouse colon mucosa.

Single xy (top) and yz (bottom) slices in samples of fresh mouse colon mucosa imaged with MediSCAPE. Contrast is derived from a, 0.01% proflavine, a nuclear dye (exc. 488 nm, em. 525/50 nm), b, 1% methylene blue, a clinically-used nuclear dye (exc. 637 nm, em. >685 nm), and c, fluorescein sodium, an FDA-approved topical and IV dye (exc. 488 nm, em. 525/50 nm). Yellow dotted lines indicate locations of corresponding cross-sections and yellow arrows indicate nuclei in insets. Depth penetration of topically applied dyes is both stain- and tissue-dependent, as shown in yz depth sections. Also shown for comparison is d, autofluorescence (exc. 488 nm, em. 525/50 nm) imaged with MediSCAPE with e, corresponding en face and depth-sectioned H&E histology of a similar region in the same colon tissue. White arrows, crypts of Lieberkühn. Red arrows, goblet cells. Scale bars 100 µm.