The Hayflick limit refers to:
Hayflick limit defines finite number of times normal somatic cells can divide before entering senescence, discovered by Leonard Hayflick and Paul Moorhead in 1961 using human fetal lung fibroblasts WI-38. They observed progressive decline in doubling capability leading to arrest after approximately 40-60 population doublings, refuting earlier claims by Alexis Carrel that cultured cells were immortal. Molecular basis is incomplete replication of linear chromosome ends due to end-replication problem: DNA polymerase cannot fully replicate 3 prime overhang, causing loss of 50-200 base pairs of tel
Ref: Hayflick L Exp Cell Res 1961 finite division; Watson et al Molecular Biology of the Gene 7th Ed Telomere shortening and replicative senescence.
