What is the Difference Between Primary Cell Culture and Cell Line

The main difference between primary cell culture and cell line is that cells in primary cell culture are directly removed from the animal or plant tissue whereas cell line is a permanently established cell culture from primary cell culture. 

Primary cell culture and cell line are two types of cell cultures with vital benefits in biotechnology and research. Furthermore, primary cell culture has a definite lifespan while cell line has an indefinite lifespan as they are immortalized. 

Key Areas Covered 

1. What is a Primary Cell Culture
     – Definition, Features, Importance
2. What is a Cell Line
     – Definition, Features, Importance
3. What are the Similarities Between Primary Cell Culture and Cell Line
     – Outline of Common Features
4. What is the Difference Between Primary Cell Culture and Cell Line
     – Comparison of Key Differences

Key Terms 

Cell Culture, Cell Line, Immortal, Parent Tissue, Primary Cell Culture

What is a Primary Cell Culture 

A primary cell line is the disassociation of cells from a parental animal or plant tissue through enzymatic or mechanical measures. It is possible to maintain these cells in a suitable substrate in glass or plastic containers under controlled environmental conditions. Some examples of primary cell culture are epithelial cells, endothelial cells, keratinocytes, melanocytes, fibroblasts, muscle cells, mesenchymal cells, hematopoietic cells, etc. Significantly, the cells in primary cell culture have the same karyotype as the cells in the parent tissue.

Figure 1: Epithelial Cells

Furthermore, the two main types of primary cell cultures based on the type of growth of cells in the primary cell culture are suspension culture and adherent culture. Moreover, primary cell cultures are harsh and they require optimized growth conditions such as addition of specific cytokines and growth factors for propagation. However, the cells in primary cell culture have a limited lifespan due to the exhaustion of substrate and nutrients, gradually increase in the level of toxic metabolites, etc. 

What is a Cell Line 

A cell line is the first subculture obtained from a primary culture. Generally, the cells of a cell line have undergone modifications such as random mutations or deliberate modifications such as the artificial expression of the telomerase gene. It makes the cells immortal with an unlimited lifespan in the culture. Also, a cell line can be maintained through serial passaging due to the indefinite lifespan. Thus, these cell lines are known as continuous cell lines. 

Figure 2: HeLa, An Immortal Cell Line

However, due to the modifications in the genetic makeup, the cells of a cell line may contain an abnormal number of chromosomes when compared to the parent tissue. Additionally, it is possible to grow tumor cells directly as cell lines since they acquire immortality through evading the checkpoints of the cell cycle.  

Similarities Between Primary Cell Culture and Cell Line 

• Primary cell culture and cell line are two types of cell cultures with different characteristic features. 
• Both contain cells removed either from animal or plant tissue and grown in an artificially controlled environment. 
• Moreover, both require nutrients and appropriate medium for growth.  
• In addition, they play a vital role in biotechnology and research. 

Difference Between Primary Cell Culture and Cell Line 

Definition 

Primary cell culture refers to the growing and maintaining of the selected cell type which has been excised from the normal parental tissue while a cell line refers to a cell culture developed from a single cell and therefore consisting of cells with a uniform genetic make-up. Thus, this is the main difference between primary cell culture and cell line.

Origin of Primary Cell Culture and Cell Line

Moreover, primary cell culture has isolated directly from the donor while cell lines are derived from primary cell culture by undergoing immortalization. 

Alterations in the Genetic Makeup 

Also, one other difference between primary cell culture and cell line is that the primary cell culture has the same genetic makeup as the parent tissue while cell line has a modified genetic makeup compared to the parent tissue. 

In Vivo Model 

Besides, another difference between primary cell culture and cell line is that primary cell culture is an in vivo model while cell line is not an in vivo model. 

Lifespan of Primary Cell Culture and Cell Line

Furthermore, the primary cell culture has a limited lifespan while a cell line has an unlimited lifespan in the culture. 

Maintenance 

Additionally, primary cell culture is unable to follow passaging while a cell line can be maintained by following passaging. 

Donor Characteristics 

Donor characteristics is also a difference between primary cell culture and cell line. The former shows donor characteristics while the latter does not show donor characteristics. 

Function 

More to these, the primary cell culture closely resembles the cell function of the parent tissue while a cell line is capable of providing consistent experimental results. 

Importance 

Primary cell culture is important in immunology, vaccination, inflammation, etc. as it closely matches the in vivo function. Meanwhile, a cell line is important to study tumor cells when the cells of interest are not available as primary cell cultures.  Hence, this is another difference between primary cell culture and cell line.

Conclusion 

In brief, primary cell culture is a type of cell culture containing cells directly obtained from the parent tissue. The main drawback of primary cell culture is its limited lifespan in the culture and its inability to subculture. However, it is important in studying in vivo function of a particular type of cells. On the other hand, a cell line is a modified type of primary cells in order to be immortalized in the culture. Therefore, the cells in a cell line have an unlimited lifespan and become capable of subculturing. Generally, cell lines can be used to study tumor cells and to modify cells for various benefits. Hence, the main difference between primary cell culture and cell line is their origin, characteristics, and importance. 

References:

1. “Primary Cell Culture Guide.” Primary Cell Culture Guide | Creative Bioarray, Available Here.
2. Kaur, Gurvinder, and Jannette M. Dufour. “Cell Lines.” Spermatogenesis, vol. 2, no. 1, 2012, pp. 1–5., doi:10.4161/spmg.19885.

Image Courtesy:

1. “Epithelial-cells” By John Schmidt (user:JWSchmidt). – wikibooks Cell Biology textbook (licensed under the GFDL) (CC BY-SA 3.0) via Commons Wikimedia   
2. “HeLa-I” By National Institutes of Health (NIH) – National Institutes of Health (NIH) (Public Domain) via Commons Wikimedia