Editing Cytotoxicity (section)

==Cell physiology==
Treating cells with the cytotoxic compound can result in a variety of prognoses. The cells may undergo [[necrosis]], in which they lose membrane integrity and die rapidly as a result of [[cell lysis]]. The cells can stop actively growing and dividing (a decrease in cell viability), or the cells can activate a genetic program of controlled cell death ([[apoptosis]]).

Cells undergoing necrosis typically exhibit rapid swelling, lose membrane integrity, shut down metabolism, and release their contents into the environment. Cells that undergo rapid necrosis in vitro do not have sufficient time or energy to activate apoptotic machinery and will not express apoptotic markers. Apoptosis is characterized by well defined cytological and molecular events including a change in the [[refractive index]] of the cell, cytoplasmic shrinkage, nuclear condensation and cleavage of DNA into regularly sized fragments. Cells in culture that are undergoing apoptosis eventually undergo secondary necrosis. They will shut down metabolism, lose membrane integrity and lyse.<ref name=riss1>{{cite journal |vauthors=Riss TL, Moravec RA |title=Use of multiple assay endpoints to investigate the effects of incubation time, dose of toxin, and plating density in cell-based cytotoxicity assays |journal=Assay Drug Dev Technol |volume=2 |issue=1 |pages=51–62 |date=February 2004 |pmid=15090210 |doi=10.1089/154065804322966315}}</ref>