He was also past president of the Gerontological Society of America and was a founding member of the council of the National Institute on Aging (NIA).

[3] This book has been translated into nine languages and is published in Brazil, the Czech Republic, Germany, Hungary, Israel, Japan, Poland, Russia, and Spain.

After receiving a post-doctoral fellowship for study at the University of Texas Medical Branch in Galveston under the tutelage of the renowned cell culturist Charles M. Pomerat (1905–1964),[8] he returned to Philadelphia, where he spent ten years as an Associate Member of the Wistar Institute and two years as an Assistant Professor of Research Medicine at the University of Pennsylvania.

Hayflick resigned from Stanford in 1976 in protest to the behavior of a few of its administrators who were later shown to have wrongly accepted the beliefs of an NIH accountant who was unable to understand the unique concept of title to a self-duplicating biological system.

[9][10] The behavior of Stanford and the NIH was later condemned by 85 prominent biologists who viewed him as having been "exonerated" by subsequent events.

[citation needed] In 1988, Hayflick joined the faculty of the University of California, San Francisco, where he was Professor of Anatomy.

He was a consultant to the National Cancer Institute and the World Health Organization, and was a member of several scientific advisory boards.

He was also recruited by Michael D. West, founder of Geron (Nasdaq: GERN) and current CEO of BioTime, to join the company's Scientific and Clinical Advisory Board, on which he served from 1991–2000.

In 1962 he discovered that, contrary to the prevailing belief at the time, cultured normal human and animal cells have a limited capacity for replication.

This discovery, known as the Hayflick limit, overturned a long-held belief bolstered by Alexis Carrel's work in the early 20th century that claimed that normal cells would proliferate continuously in culture.

WI-38, or new diploid cell strains, are used today for the manufacture of most human virus vaccines produced throughout the world including those for poliomyelitis, rubella, rubeola, varicella, mumps, rabies, adenoviruses and hepatitis A.

[16] The etiological agent was first thought to be a virus, but Hayflick showed that it was, in fact, a mycoplasma, a member of the smallest free-living class of microorganisms.

[citation needed] In the mid-1990s, Hayflick was recruited by Geron founder Michael D. West to join the company's Scientific Advisory Board.

Hayflick was the recipient of the 2001, $10,000 Life Extension Prize and Laureate Diploma from the Regenerative Medicine Secretariat for his "...discovery of the finite replicative capacity of normal human diploid cells..." A third Annual Hayflick Lecture was established at the Friedrich Schiller University in 2013.

[citation needed] Hayflick was a Fellow of the American Association for the Advancement of Science, an Honorary Member of the Tissue Culture Association and, according to the Institute of Scientific Information, is one of the most cited contemporary scientists in the world in the fields of biochemistry, biophysics, cell biology, enzymology, genetics and molecular biology.