The life science research has taken a major turn with the introduction of cell lines and culturing techniques. A number of experiments are performed with cell lines in order to understand the behaviour of cells under different conditions that provide valuable complement to in vivo experiments and play a critical role in scientific advancements.
Researchers prefer to use cell lines in experiments as they are generally highly proliferative and easy to culture and transfect. However researchers need to be very cautious when interpreting data generated from cell lines due to limitations associated with cell lines such as modified phenotype, genetic make-up, chromosome aberrations etc. These shortcomings inclined researchers to adopt the primary cells in their research experiments. Primary cells are cells derived from specific species so they closely mimic in vivo environment.
To better understand primary and continuous cell lines, it is important to know differences between them-
Derivation: Primary cells are cells derived from specific organ of a specific species with mechanical or enzymatic digestion method. A cell line is developed with continuous passaging of primary cells to obtain a cell line.
Life span: Primary cells have a finite life span i.e. they divide only limited number of times. Cell lines have longer life span and they can be passaged indefinitely.
Genetic makeup: As primary cells have shorter lifespan thus ensuring genetic and phenotypic consistency with the source organism. Serial passage of cell lines causes genotypic and phenotypic variation over an extended period of time. Most of the cell lines are being used in culture since long time and are well adapted to the two-dimensional culture environment, and as a result, differ genetically and phenotypically from their tissue origin and also show altered morphology.
Ease of use: Primary cells need optimized media and conditions for optimal growth; however continuous cell lines can be cultured in established and robust environment.
Data relevance: As primary cells closely mimic the in vivo environment; their uses in research provide more relevant and meaningful data. With use of cell lines, relevance of data can drift over time as cells divide (minimal biological relevance).
In conclusion, it can be difficult to culture primary cells; however data obtained with primary cells is more relevant and meaningful in comparison to continuous cell lines.