This 3D tissue imaging video shows an intact mouse colorectal tumor imaged using light sheet fluorescence microscopy. Immune cells are visualized in their native spatial context with B220 labeling B cells in green and CD3 labeling T cells in magenta.

Single immune cells are resolved while preserving full tissue architecture, enabling analysis across scales from cellular detail to tissue-level organization. Imaging the complete volume avoids sampling bias associated with serial sectioning and reveals spatial relationships that are lost in 2D workflows.

This staining approach can be applied across tissue types to identify tertiary lymphoid structures and characterize immune organization in 3D. The result is volumetric ground-truth data that supports quantitative analysis of immune contexture within intact tissue.