Example of biosensor

Caspase 3 biosensor

This biosensor is a chimeric construct composed of a GFP like protein linked to a mitochondria anchorage probe by a peptide bond specifically cleaved by Caspase 3.

Biosensor in action

When caspase 3 is inactivated (by a drug compound, for example), the fluorescent biosensor protein locates to the mitochondrial outer membrane (MOM) and its fluorescence remains in the cell after plasma membrane permeabilization.

In contrast, when caspase 3 is active, the biosensor is cleaved; the GFP-like protein relocates to the cytoplasm and can be removed from the cell after plasma membrane permeabilization.