ABSTRACT
As a classic fluorescent detect technique, fluorescence resonance energy transfer (FRET) has been widely used in biological researches. Researchers have developed a series of fluorescence detect probes which were based on FRET. Caspase family plays an important role in apoptosis pathway, especially Caspase-8 which located, at the initial of death receptor mediated apoptosis pathway, whose its activation can trigger subsequent precaspases' activation and lead to apoptosis. So it is of great significance to detect the activation of Caspase-8 in apoptosis assay. In this study, a fluorescent probe based on FRET has been designed which can detect the activity change of Caspase-8 in cells. To identify the effectiveness and specificity of the probe, we measure the Caspase-8 activity under the Caspase-8 specifically activated apoptosis inducer RGD-TRAIL with the flow cytometry FRET detection platform. The results show that the probe can respond to the activity change of Caspase-8 in apoptotic cells, and the change can be quantified rapidly by flow cytometry. The study provides a more efficient and convenient detection method of Caspase-8 activity in living cells.