Definition
Growing cells under controlled laboratory conditions outside the organism, a core in vitro research method.
Cell culture is the maintenance and growth of cells in an artificial environment, typically in plastic vessels with nutrient medium at 37 °C and 5% carbon dioxide. Primary cells come directly from tissue and have a limited lifespan, while immortalised cell lines, such as HEK293 or HeLa, divide indefinitely and are often engineered to express a receptor of interest. Three-dimensional cultures and organoids better reproduce tissue structure. Good practice includes authenticating cell lines, testing for mycoplasma contamination and recording passage numbers. When testing peptides, researchers control for vehicle effects, counter-ions such as TFA, preservatives such as benzyl alcohol and endotoxin, any of which can alter readouts.