Cell strains

A cell strain is derived either from a primary culture or a cell line by the selection or cloning of cells having specific properties or characteristics which must be defined. Cell strains are cells that have been adapted to culture but, unlike cell lines, have a finite division potential. Non-immortalized cells stop diving after 40 to 60 population doublings and, after this, they lose their ability to proliferate (a genetically determined event known as senescence).