Cytotoxicity is one of the most common biological parameters measured after experimental manipulation largely because it is easily measured and adheres to the dose-dependence paradigm of Paracelsus. It is well known that many drugs produce physiological and therapeutic actions at lower concentrations while the toxic effects including necrosis or apoptosis occur at higher concentrations. Regardless of the mechanism of cell death, mammalian cells after interacting with toxins undergo a series of dramatic structural and morphological changes that lead to loss of membrane integrity (Leist, 2001). This irreparable damage to cellular architecture allows free movement of previously excluded molecules into the cell, as well as their enzymatic contents to leak into the culture medium (Riss, 2004). Therefore, measurement of intracellular enzyme marker activity in the extra-cellular environment is the basis of several cytotoxicity assays for accessing cell membrane integrity.