HeLa cells are certainly the most famous. It should be noted that the HeLa stocks used in most labs now are radically different from original HeLa stocks.
Even in routine experiments, you have to keep a bunch of cells frozen in liquid nitrogen to replenish your "working stock" of cells. After around 30-40 passages (e.g. generations of cells), most immortalized cell lines start to get funky with mutations and exhibit different behaviors. You kill them off and go back to your frozen stocks to get back to the "original" genetics.
HeLa cells are certainly the most famous. It should be noted that the HeLa stocks used in most labs now are radically different from original HeLa stocks.
Even in routine experiments, you have to keep a bunch of cells frozen in liquid nitrogen to replenish your "working stock" of cells. After around 30-40 passages (e.g. generations of cells), most immortalized cell lines start to get funky with mutations and exhibit different behaviors. You kill them off and go back to your frozen stocks to get back to the "original" genetics.