Cell Culture

• Cell culture is the technique of growing living cells outside the body in controlled laboratory conditions so scientists can study, test, and manipulate them safely and precisely.
• Maintaining and growing cells in a nutrient-rich artificial environment
• Cells can come from plants, animals, or humans.
• Cultures allow scientists to observe cell behaviour without the complexity of an entire organism.

• Medical research – studying diseases, cancer, immune responses.
• Drug testing – checking toxicity and effectiveness before human trials.
• Genetic studies – observing gene expression and mutations.
• Vaccine production – many vaccines are grown in cultured cells.
• Biotechnology – producing proteins, hormones, antibodies.
• Requirements for Successful Cell Culture
• Sterile conditions – no contamination from bacteria, fungi, or viruses.
• Nutrient medium – provides glucose, amino acids, vitamins, salts, growth factors.
• Controlled environment – correct temperature, pH, oxygen, CO₂ levels.
• Appropriate container – flasks, Petri dishes, multi-well plates.
• Regular monitoring – checking cell shape, density, colour of medium.

• Primary culture – cells taken directly from tissue; limited lifespan.
• Cell lines – cells that divide continuously (e. g., HeLa cells).
• Adherent cultures – cells attach to the surface (common for animal cells).
• Suspension cultures – cells float freely (common for blood cells).
• Aseptic Technique:

• Work near a Bunsen burner or inside a laminar flow hood.
• Sterilise equipment using autoclaves, ethanol, or UV light.
• Flame or sterilise loops, pipettes, and necks of bottles.
• Wear gloves, lab coat, and tie back hair.
• Avoid talking or moving hands over open containers.

• Temperature:
• For Human/animal cells → ~37°C
• For Plant cells → ~25°C
• pH: around 7.2–7.4
• CO₂: 5% for mammalian cells (keeps pH stable)
• Medium colour: Pink/red = healthy pH, Yellow = acidic (overgrowth or contamination)
• Purple = too alkaline

• Confluence – percentage of surface covered by cells.
• Morphology – shape and appearance (round, elongated, spread out).
• Ethical considerations in using human/animal cells.

Cloudy medium, Floating debris, Sudden pH change, Unusual smell