FIGURE 2.

Expansion microscopy improves antibody penetration into tumor spheroids. Central sections of expanded GBM#18 tumor spheroids expressing a cytosolic tdTomato fluorescent protein (A), line profile of fluorescent intensity through the center of a cleared or expanded spheroid (endogenous tdTomato signal) (B), line profile of fluorescent intensity through the center of a cleared or expanded spheroid (anti-tdTomato immuno-stain signal) (C). Fluorescence (AU) was normalized and distance of the expanded spheroids was normalized to that of the cleared spheroid. Scale bar: 50 μm (cleared), 200 μm (expanded).