FIG. 2.

Fluorescent DsRed signaling as an indicator of hypoxia-inducible transcription factor activity over 5 days in 5k (top left), 10k (top right), 20k (bottom left), and 60k (bottom right) ADSC spheroids incubated in 20%, 2%, or 1% O₂. The relative extent of signaling is quantified in the graph above each set of figures by applying a signal intensity threshold value. The voided region caused by spheroid condensation can be seen as a ring in the hydrogel around the culture in some images. Scale bar=500 μm. Color images available online at www.liebertpub.com/tea