What are the advantages of protease viability marker assay?

Protease viability marker assay is based on the principle that protease activity is rapidly lost when cells die. Advantages of protease viability marker assay include: 

• It is relatively nontoxic to cells in culture. 
• There is little change in the viability of cells on long-term exposure of the GF-AFC substrate. 
• It has a short incubation time of about 30 minutes to 60 minutes. 
• Cell population remains viable at the end of the protease viability marker assay and can be used for subsequent assays, making this assay suitable for multiplexing with other assays.