FLIVO® kits provide a simple and accurate method to detect caspase activity in vivo. Similar to our FLICA® probes but optimized for whole live animal labeling. To label cells containing active caspases, inject FLIVO intravenously and let it circulate ~60 minutes. Because the reagent is cell-permeant, it readily diffuses in and out of all cells that it encounters as it circulates throughout the body. If there are active caspase enzymes inside a cell, FLIVO will form an irreversible covalent bond with the caspase active site. The bound FLIVO probe will remain inside the cell if the cell membrane is intact. Any unbound FLIVO is removed from the circulation of the animal in about an hour. The remaining red fluorescent signal in the tissue is a direct measure of caspase activity that occurred at the time the reagent was injected. Once the excess FLIVO has cleared from the body of the animal, the tissues are ready for analysis. No further staining is necessary. Tissues can be viewed directly through a window chamber system or other accessible cavity. Alternatively, target tissues can be removed and processed for analysis. FLIVO is very sensitive and will pick up naturally occurring background apoptosis. Apoptotic cells have more active caspases than control cells, therefore they fluoresce brighter with FLIVO.
