Leonard Hayflick

Dr. Leonard Hayflick discovered the doubling limit of normal human cells, its' interpretation as aging or senescence, the immortality of cancer cells, and normal cell memory. He also invented the normal human cell strain WI-38 used world-wide to prepare most human virus vaccines. He discovered Mycoplasma pneumoniae, (the smallest free-living microorganism) to be the cause in humans of Primary Atypical Pneumonia (Walking Pneumonia). He is a Professor of Anatomy at the UCSF School of Medicine and founding member of the Council of the National Institute on Aging, NIH.

Dr. Hayflick received his PhD from University of Pennsylvania in Medical Microbiology.