Cell culture is a process where cells (animal or plant cells) are removed from the organism and introduced in to an artificial environment with favorable conditions for growth. This allows for researchers to study and learn more about the cells.
There are three major types of cell culture, which include:
- Primary cell culture
- Secondary cell culture, and
- Cell line
Here, we shall focus on primary cell culture.
There are two types of primary cells:
Adherent cells – Also referred to as anchorage dependent cells, these are the type of cells that require attachment for growth. Adherent cells are immobile, and obtained from such organs as kidney.
Suspension cells – These are the type of cells that do not require attachment in order to grow. They are therefore also referred to as anchorage independent cells, and include such cells as lymphocytes found in the blood system.
In primary cell culture, cells obtained from such parental tissues (living tissues) as the liver and kidney, are introduced into suitable media for growth. Once the cells have been obtained, they can either be cultured as explants culture, suspension or monolayer.
* In primary cell culture, the cells must have been obtained from the parental/living tissue. That is, they are not from another culture process.
Before the cells are cultured, they are first subjected to enzymatic treatment for dissociation. However, has to be for a minimal amount of time to avoid damaging or killing the cells. Once single cells are obtained, they are then appropriately cultured in media to allow them to grow (divide) are reach the desired numbers.
Initially, the culture tends to be heterogeneous in that it’s composed of different types of cells obtained from the tissue. Although this can be maintained through the in vitro process (in a culture in a suitable media) this would only be for a limited period of time.
Through the transformation process, the primary cells may be used for a long period of time, changing the culture over time. These cells are refers to as continuous cell lines.
However, primary cells are typically preferred over continuous cell lines because of the fact that they are more similar (physiologically) to in vivo cells (cells from the living tissue). In addition, continuous cell lines may undergo certain changes (phenotypic and genotypic changes) which would result in discrepancies during analysis. As such, they cannot be used to determine what is happening to the in vivo cells. It’s for this reason that primary cells are preferred.
Given that the primary cells significantly resemble the cells obtained from living tissue, they are important for research purposes in that they can be used to study their functions, metabolic regulations, cell physiology, development, defects and conditions affecting the tissue of interest.
Also, they are used for such purposes as vaccine production, genetic engineering drug screening as well as toxicity testing and prenatal diagnosis among others.