Write a brief account on primary cell culture

Primary cell culture refers to the process of isolating cells directly from animal tissues and growing them in a suitable artificial environment under controlled laboratory conditions. These cells are taken from a living organism and maintained in vitro for a limited period. Since they closely mimic the in vivo state, primary cells are considered more physiologically relevant than immortalized cell lines. However, they have limited lifespan and can divide only for a few generations. Primary cell culture is widely used in cell biology, pharmacology, toxicology, cancer research and vaccine production because of its close resemblance to natural cell behavior in organisms.

Types of Primary Cells (Based on Growth Behaviour):

There are two main types of primary cells depending on how they behave during growth in culture:

1. Adherent Cells / Anchorage-Dependent Cells:

  • Adherent cells, also known as anchorage-dependent cells, are those which require a solid surface to attach, spread and grow. These cells are mostly derived from organs and tissues like kidney, liver, fibroblasts and epithelial tissues. They grow in monolayers and cannot survive or divide without proper attachment to a substrate like tissue culture-treated plastic or glass. Growth stops when the surface area is completely occupied (contact inhibition). Subculturing them involves enzymatic digestion using trypsin or EDTA to detach them. These cells are widely used in drug testing, virology and cancer research.

2. Suspension Cells / Anchorage-Independent Cells:

  • Suspension cells, also called anchorage-independent cells, can grow and divide freely in suspension without needing any solid surface to attach. These are usually isolated from blood or lymphoid organs, such as lymphocytes or certain myeloma cells. These cells grow as single cells or small clumps floating in the culture medium. They are ideal for large-scale cultures in bioreactors because they do not require enzymatic harvesting. These are especially useful in immunological research, vaccine production and monoclonal antibody generation. Their handling is easier and they can be passaged simply by dilution.

Steps Involved in Primary Cell Culture Preparation:

1. Tissue Collection:

  • A fresh tissue sample is collected from an animal under sterile conditions. Common sources include liver, kidney, lung, or skin. The sample is transported quickly to the lab in a suitable transport medium

2. Tissue Washing and Trimming:

  • The tissue is washed multiple times with sterile PBS (phosphate-buffered saline) to remove blood, fat and debris. It is then cut into small pieces using sterile instruments.

3. Tissue Disaggregation:

  • To release individual cells, the tissue is disaggregated either by enzymatic digestion using enzymes like trypsin, collagenase, or dispase, or by mechanical methods like pipetting or mincing.

4. Filtration and Centrifugation:

  • The cell suspension is filtered to remove large clumps and debris. Then it is centrifuged to collect viable cells at the bottom.

5. Seeding and Culturing:

  • The collected cells are suspended in a suitable culture medium and seeded into culture flasks or plates. Adherent cells attach to the surface, while suspension cells remain in the medium.

6. Incubation and Maintenance:

  • The cultures are incubated at 37°C with 5% CO₂. The medium is changed regularly to provide nutrients and remove waste. Cells are monitored for growth and contamination.
Primary cell culture refers to the process of isolating cells directly from animal tissues and growing them in a suitable artificial environment under controlled laboratory conditions. These cells are taken from a living organism and maintained in vitro for a limited period. Since they closely mimic the in vivo state, primary cells are considered more physiologically relevant than immortalized cell lines. However, they have limited lifespan and can divide only for a few generations. Primary cell culture is widely used in

Benefits of Primary Cell Culture:

  • High physiological relevance: They closely resemble cells inside the body, so results are more accurate for in vivo studies.
  • Useful in toxicity and drug screening: Since they respond naturally to stimuli, they are preferred in pharmacological testing.
  • Vaccine and protein production: Many vaccines, like polio and rabies, are made using primary cell cultures.
  • Genetic studies: They are used to study gene expression in normal cells before transformation.
  • Model for disease study: Cells from diseased tissues can be cultured to study pathological conditions directly.

Drawbacks of Primary Cell Culture:

  • Limited lifespan: They divide only a few times before entering senescence.
  • More variation: Each preparation may show variability depending on the donor or isolation method.
  • Sensitive to conditions: They are highly sensitive to culture conditions like temperature, pH, and contamination.
  • High cost and effort: Isolation and maintenance require sterile conditions, time, and expensive equipment.
  • Ethical issues: Tissue collection from animals may raise ethical concerns.






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