Fig. 3: BS-IDT imaging on bladder cancer cells.

a–k 3D chemical imaging of fixed bladder cancer T24 cells under mitosis. The medium is D₂O PBS. The scale bar in “e” is applicable to “a” to “e”. a Depth-resolved cold imaging results. b–e Depth-resolved chemical imaging results. For “a” to “e”, images in each row are from the same depth. For “b” to “e”, images in each column are under the same mid-IR laser illumination conditions. b Protein imaging results with 1657 cm⁻¹ mid-IR wavenumber. c Lipid imaging results with 1745 cm⁻¹ mid-IR wavenumber. d Control tests: off-resonance imaging results with 1900 cm⁻¹ mid-IR wavenumber. Most biochemical compounds have significantly weak or no absorptions at this wavenumber. e Control tests: chemical imaging results without mid-IR illumination. f Cold imaging results of the dash-line square area in “a”. g Overlay chemical imaging results of the dash-line square area in the dash-line square area of “a”. The scale bar in “g” is for both “f” and “g”. h–k 3D reconstructions of the cells shown in “a”, “b”, and “c”. l Mid-IR Fingerprint spectra extracted from protein and lipid-rich areas as well as areas without cells. The chemical images below “m” show the areas of interest highlighted with different colors and indicated by white arrows. m Statistical results of lipid content volume measured from T24 cells and SW780 cells. T24 is an invasive bladder cancer cell line. SW780 is a non-invasive bladder cancer cell line. 30 independent cells were used for each cell type. The volumes of lipids were independently measured and extracted 30 times per cell type.