<i>In vitro</i> detection of apoptosis.

<p>Cells were incubated with cisplatin (300 ng/ml), cetuximab (200 µg/ml), and cisplatin (300 ng/ml) plus cetuximab (200 µg/ml) in combination for 24 h. Cells were harvested and incubated with FITC-labeled ApoPep-1 at 4°C for 1 h or with annexin V at room temperature for 15 min. Data represent percentages of apoptotic cells as measured by flow cytometry. (A-C) Percentages of apoptotic cells detected by linear form of ApoPep-1, cyclic form of ApoPep-1, and annexin V, respectively. PBS, phosphate-buffered saline; CPT, cisplatin; CET, cetuximab; CPT+CET, cisplatin plus cetuximab.