Immortality of Hela cells

HeLa cells are termed "immortal" in that they can divide an unlimited number of times in a laboratory cell culture plate as long as fundamental cell survival conditions are met (HeLa cells have an active version of the enzyme telomerase during cell division, which prevents the incremental shortening of telomeres that is implicated in aging and eventual cell death). HeLa cells persist because they have always been helped along by a certain human element in science, an element connected to emotions, egos, a reluctance to admit mistakes. HeLa cells are apparently so aggressive in growth that a slight contamination by these cells can result in their overwhelming other cultures.

There are many strains of HeLa cells as they continue to evolve by being grown in cell cultures, but all HeLa cells are descended from the same tumor cells removed from Mrs Lacks. HeLa cells circumvent the Hayflick Limit, which is the limited number of cell divisions that most normal cells can undergo before dying in cell culture. It has been estimated that the total number of HeLa cells that have been propagated in cell culture far exceeds the total number of cells that were actually in Henrietta Lacks' body. Because of their avid adaptation to growth in tissue culture plates, HeLa cells are sometimes difficult to control.