Cell viability and proliferation are related but distinct cellular characteristics. Viability refers to the number of living cells in a population, while proliferation describes the rate at which cells divide and increase in number. Crucially, not all viable cells are actively proliferating.
Understanding Cell Viability
Cell viability is a measure of how many cells in a sample are alive and functioning normally. This is often expressed as a percentage of the total cell population. Several techniques exist to determine cell viability, including assays that assess membrane integrity, metabolic activity, or the presence of specific cellular components. A high viability percentage indicates a healthy cell population. Learn more about cell viability assays.
- Example: A cell culture with 95% viability indicates that 95% of the cells are alive and functional.
Understanding Cell Proliferation
Cell proliferation, on the other hand, focuses on the rate of cell division. It reflects how quickly a cell population is growing. Measuring proliferation can involve techniques that track cell numbers over time, DNA synthesis, or metabolic activity. High proliferation indicates rapid cell growth. Explore different cell proliferation assays here.
- Example: A rapidly proliferating tumor cell line might double its population size every 24 hours.
Key Differences Summarized
| Feature | Cell Viability | Cell Proliferation |
|---|---|---|
| Definition | Number of living cells in a population | Rate of cell division and population increase |
| Measurement | Membrane integrity, metabolic activity, etc. | Cell counting, DNA synthesis, metabolic activity |
| Relationship | All proliferating cells are viable, but not all viable cells proliferate | Dependent on cell viability |
A cell can be viable but not proliferating. For example, cells may be in a resting phase (G0 phase of the cell cycle) and not actively dividing, yet remain alive and metabolically active. Conversely, a decrease in the number of viable cells can be due to either cell death or inhibition of cell proliferation (cytostatic effect). (Nature, 2022)
