Infrared Spectroscopic Imaging: Label-free Biochemical Analysis of Stroma and Tissue Fibrosis.

•Infrared (IR) spectroscopy measures how a tissue’s chemical bonds absorb infrared radiation at different wavelengths.•IR absorption at multiple wavelengths creates a spectrum, or a biochemical signature of a tissue’s disease state.•IR spectroscopic tissue imaging uses microscopy to provide a spectrum for every single pixel in an imaged tissue.•This image data allows for the selective extraction of the biochemical signatures from key tissue components.•Areas of stroma and fibrosis in tissue samples provide rich new IR targets for acquiring information about disease processes.