Figure 3. Rapid intra-operative microscopy of fresh human breast.

a,b, A freshly excised specimen of human breast tissue (2.0 × 2.0 × 0.4 cm) was stained with acridine orange for 20 sec and then imaged with the open-top light-sheet microscope at a speed of v = 12.5 sec/cm². The tissue was subsequently submitted for conventional histology. c, A surface-extracted image acquired in <1 min with representative line profiles of the tissue-surface depth, d. In (a–c) the inset arrows denote a region of invasive carcinoma (i.e. a positive margin). e, Moderate- and high-magnification images reveal a transition from benign breast tissue to invasive ductal carcinoma. f, Benign breast lobules are clearly visualized (inset arrows) and correlate with conventional histology. g, Open-top light-sheet microscopy, conventional histology, and frozen-sectioning of fibro-adipose tissue. Open-top light-sheet microscopy images and FFPE histology sections both reveal adipocytes and strands of fibrous tissue with stromal cells, whereas the frozen section contains distorted fibrous tissue and adipocytes that are distorted by the process (inset arrows).