Pros of membrane permeability assays: 

• Membrane permeability assays are generallyquick and straightforward to perform.
• Results can be obtained in a relatively short period of time.
• Exclusion dye propidium iodide has a very bright color making it easy to distinguish live cells from dead cells.
• Membrane permeability assays are versatile in that they can be used with a wide range of cell types. They can also be adapted to many different experimental conditions.
• The quantitative measure of cell viability and cytotoxicity can be easily obtained by quantifying the extent of membrane permeability. 
• Many membrane permeability assays utilize commonly available reagents, making them cost-effectiveoptions for determining viability and cytotoxicity.