Fig. 3. Western blot and densitometric analysis of PARP content in normoxic and hypoxic human corneal epithelial cells. HCE-T were cultured for 7 days under normoxic (N) or hypoxic (H) conditions. 15 µg of cell lysates were resolved using 7.5% SDS-PAGE and processed for western blot analysis using mAb to PARP. Both the 115 kDa full-length PARP and the 89 kDa PARP cleavage product characteristic of apoptosis are detected by immunoblot. The relative density values of each PARP species determined by densitometry are indicated (in arbitrary units/µg total protein) to the right of each protein. The total of the densitometry readings is also indicated.