Cell line

Definition

A cell line is a population of cells that can be cultured and propagated indefinitely in the laboratory, derived from a single cell or tissue sample. These cells undergo transformation, allowing them to divide continuously while maintaining their specific characteristics. This ability to replicate endlessly makes cell lines essential for various research applications, including drug testing, genetic studies, and cancer research.

5 Must Know Facts For Your Next Test

1. Cell lines can be derived from various sources, including tumors, embryonic tissues, or established cell types, enabling diverse research applications.
2. They are categorized into two main types: continuous cell lines, which grow indefinitely, and finite cell lines, which have a limited number of divisions before senescence.
3. Commonly used cell lines include HeLa cells, derived from cervical cancer cells, and NIH 3T3 cells, which are fibroblast cells used extensively in molecular biology studies.
4. Cell lines must be regularly tested for contamination with bacteria, fungi, or mycoplasma to ensure experimental integrity and reproducibility.
5. The characteristics of a specific cell line can vary due to genetic drift over time, making it crucial for researchers to document the source and passage number of the cell line used.

Review Questions

• How do cell lines differ from primary cultures in terms of longevity and usage in research?
  • Cell lines differ from primary cultures primarily in their longevity and ability to proliferate. While primary cultures consist of freshly isolated cells that typically have a limited lifespan due to senescence, cell lines can be maintained indefinitely through continuous subculturing. This makes cell lines more versatile and reliable for long-term experiments and various applications in research like drug testing and genetic studies.
• What role does immortalization play in the establishment of a cell line, and what techniques are commonly used for this process?
  • Immortalization is crucial for establishing a cell line as it allows normal cells to bypass senescence and proliferate indefinitely. Techniques such as introducing specific oncogenes or inhibiting tumor suppressor genes are commonly employed for this purpose. Additionally, exposure to certain viruses or chemical agents can also induce immortalization, transforming normal cells into continuously dividing cell lines suitable for extensive laboratory use.
• Evaluate the implications of genetic drift on the use of established cell lines in scientific research and how researchers can mitigate these effects.
  • Genetic drift can significantly impact the use of established cell lines by altering their characteristics over time, potentially leading to inconsistent results in experiments. This variability poses challenges for reproducibility and reliability in research findings. To mitigate these effects, researchers should maintain detailed records of the passage history of their cell lines, regularly authenticate their identity using molecular techniques, and periodically refresh their cultures from original stocks to minimize drift-induced changes.

Related terms

Primary culture: A primary culture consists of cells taken directly from a living organism and cultured for the first time, usually having a limited lifespan compared to established cell lines.

Immortalization: Immortalization refers to the process by which cells acquire the ability to proliferate indefinitely, often achieved through genetic manipulation or exposure to certain substances.

Subculturing: Subculturing is the process of transferring cells from one culture vessel to another to maintain growth and viability, often done with established cell lines to ensure they continue to thrive.