What animal cell culture is

Animal cell culture means keeping animal cells alive and dividing outside the body (in vitro), in a suitable medium. A population of cells that all came from one parent cell is a clone: the cells are genetically identical.

Animal cells divide slowly, about once every 18-24 hours. A single bacterium, dividing every 20 minutes, would soon outgrow them, so working aseptically (keeping out every microbe) is vital.

The first human cell line has a famous and troubling story. In 1951, George Gey took cervical cancer cells from a patient, Henrietta Lacks, without her permission. Unlike normal cells, they kept growing indefinitely. Called HeLa cells, they became the first human cell line, used in research from radiation studies to testing the polio vaccine, and earned large profits for others, while her family knew nothing for years. Her story raised lasting questions about consent in medical research.

Large-scale cell culture grew with the need for viral vaccines, since viruses can multiply only inside living cells. Scientists discovered the growth factors cells need (nerve, epidermal, insulin-like, fibroblast, platelet-derived and transforming growth factors), and from 1976 developed serum-free media.

Some milestones:

• 1882: Ringer's salt solution kept tissues alive.
• 1907: Harrison grew frog nerve fibres in culture.
• 1912: Carrel developed aseptic techniques.
• Later: laminar air-flow cabinets; defined media (Eagle); HAT selection (Littlefield); and the first hybridoma (Köhler and Milstein, 1975).