Figure 3: Hypoxia induced changes in ECM protein expression differed depending on the context of culture. (A) Analysis of collagen I and fibronectin protein expression in the conditioned media of hypoxia and atmospheric-exposed co-cultures. Ponceau S (Ponc-S) was utilized as a loading control (B) Western blots of collagen I, fibronectin, collagen IV and laminin in the de-cellularized hypoxic and atmospheric ECM. GAPDH was utilized as a loading control.