- Animal cell culture is the process of growing animal-derived cells outside their natural biological context under controlled laboratory conditions. This technique has become fundamental in cell biology, molecular biology, biotechnology, and medicine.
- By isolating cells from tissues or tumors and providing them with an artificial but supportive environment—including nutrients, growth factors, and suitable physical conditions—researchers can observe, manipulate, and utilize cellular behavior in a reproducible and ethical way. The in vitro setting allows for detailed analysis of cellular processes that would be difficult or impossible to study within a living organism.
- Successful animal cell culture relies on maintaining precise environmental parameters. Most mammalian cells require a temperature of 37°C, a near-neutral pH (around 7.2–7.4), a humidified atmosphere with 5% CO₂ to maintain bicarbonate-buffered media, and an osmotically balanced medium enriched with essential nutrients. Culture media typically include amino acids, vitamins, salts, glucose, and growth-promoting additives such as fetal bovine serum (FBS). To prevent contamination, all procedures must be conducted using aseptic techniques under sterile conditions, often in laminar flow hoods.
- Animal cell cultures are broadly classified based on their origin and lifespan. Primary cultures are established directly from tissues and retain many of the characteristics of the tissue of origin, but they have limited proliferative capacity. Once subcultured, these cells are considered secondary cultures. Some cells undergo spontaneous or induced transformation, becoming continuous or immortalized cell lines capable of proliferating indefinitely. Widely used examples include HeLa, CHO, and HEK293 cells. Stem cells—both embryonic and induced pluripotent stem cells (iPSCs)—form another major category, with the potential to differentiate into various specialized cell types under defined culture conditions.
- Depending on their nature, cells can be cultured as adherent monolayers or in suspension. Most mammalian cells require attachment to a surface such as plastic or glass, while some (e.g., lymphocytes or transformed cells) can grow freely in suspension. More complex systems include co-cultures of multiple cell types to study interactions, microcarrier-based cultures for scaling adherent cells in bioreactors, and three-dimensional (3D) cultures or organoids that better mimic in vivo tissue architecture. These advanced models have improved the physiological relevance of in vitro studies and are particularly valuable for drug discovery and regenerative medicine.
- Animal cell culture supports a wide range of applications. In basic research, it enables the study of cell signaling, gene expression, differentiation, and disease mechanisms. In biotechnology and pharmaceutical industries, cultured cells are used to produce recombinant proteins, monoclonal antibodies, and vaccines. CHO and HEK293 cells, for instance, are common hosts for biologic drug manufacturing. In clinical and translational research, cultured cells are employed in gene therapy, tissue engineering, and personalized medicine. Patient-derived cells and iPSCs are increasingly used to model genetic diseases, predict drug responses, and develop individualized therapies. Cell culture also provides a platform for toxicological testing, offering an alternative to animal testing in cosmetics, chemicals, and drug development.
- Despite its advantages, animal cell culture has limitations. Cells maintained in vitro may undergo genetic or phenotypic changes over time and may not fully replicate the behavior of tissues in vivo. Simple 2D cultures lack the complex structural and biochemical cues present in living organisms. In addition, the use of serum introduces variability and potential ethical concerns. Contamination by bacteria, fungi, or mycoplasma remains a persistent challenge in many laboratories.
- Recent innovations are addressing these challenges and pushing the field forward. Advances in automation and artificial intelligence are enabling high-throughput, standardized cell culture systems. Microfluidic technologies have led to the development of “organ-on-a-chip” platforms that simulate the dynamic microenvironment of tissues and organs. Defined, serum-free media are replacing animal-derived supplements to improve reproducibility and regulatory compliance. Gene editing tools like CRISPR have made it easier to create disease models or engineer therapeutic cell lines. Emerging fields like 3D bioprinting and 4D culture systems are creating dynamic, spatially organized environments that closely mimic in vivo tissue structure and function.
