Difference Between Primary Cell Culture and Cell Line

Key Difference – Primary Cell Culture vs Cell Line
 

The field of Research has taken a major twist with the introduction of cell culturing and the use of cell lines for research. Different tests are done on artificially prepared cells and cell lines in order to assess the behaviour of the cell. Most human-based research requires cell culturing and cell lines to validate the results, especially when the research studies are based on pharmacology and drug discovery. Primary cell culture is a culture prepared by direct isolation of cells via mechanical or enzymatic methods. A cell line is prepared by continuously passaging a primary cell culture to obtain a cell line that has acquired homologous characters. The key difference between the primary cell culture and the cell line is the number of passaging times each of them possess. The primary cell culture is directly isolated whereas a cell line is prepared by passaging a primary cell culture for several times.

CONTENTS

1. Overview and Key Difference
2. What is a Primary Cell Culture
3. What is a Cell Line
4. Similarities Between Primary Cell Culture and Cell Line
5. Side by Side Comparison – Primary Cell Culture vs Cell Line in Tabular Form
6. Summary

What is a Primary Cell Culture?

Primary cell culture is a cell culture preparation by isolating cells directly from the source via mechanical or enzymatic methods. The cells are isolated by trypsinization or non – trypsinization methods. The primary cell cultures are grown in suitable growth media that contain growth factors, hormones, lipids and other undefined components. Certain media have to be accompanied by serum. The media ensure that the conditions for growth are optimized, and the cells survive at optimum conditions. Cells can be isolated from different tissue sources such as liver tissue, endothelium and neural tissue in humans or higher animals via trypsinization.

When isolating cells from plants and microorganisms, special extraction procedures are used, which use both mechanical and chemical methods. These isolated cells can be immobilized onto a solid support or can be passaged for several generations to be developed into a cell line.

Primary cell cultures are mainly of two types; Adherent cell cultures and suspension cell cultures. Adherent primary cell cultures are anchorage-dependent, and they require solid support for the growth. The adherent primary cell cultures are mainly derived from tissues or organs. The suspension primary cell cultures are anchorage-independent, and they grow in liquid media. The suspension cultures should be continuously agitated during the growth phase. The suspension primary cell cultures can be straightly derived from blood.

Primary cell cultures have a relatively less lifespan, but the information derived from primary cell cultures under in vitro conditions provides the basic foundation for many studies. They are useful to study the cell characteristics, both morphological and chemical behaviour.

What is a Cell Line?

Cell lines are widely used in research and at present cell lines such as cancer cell lines, liver cell lines and kidney cell lines are commercially available for research purposes. The cell lines are prepared by continuous passaging of primary cell culture. Passaging refers to the subculturing process where the cell cultures are developed into a cell line. These cell lines are cultures in a two – dimensional or three – dimensional matrices and maintained as cell lines.

Cell lines are classified as finite and continuous cell lines. Finite cell lines are subjected to a definite number of passages (20 – 30 passages). Upon completion of the required number of passages, the cell line enters a stage of senescence. These cells are easy to handle as their growth is definite. The continuous cell lines are also referred to as immortalized cell lines. These cell lines do not have a definite number of passages. They grow indefinitely and thus are able to acquire mutations. Therefore, continuous cell lines are easily mutated and thus, they change in their morphological and genetic characteristics, unlike in finite cell lines.

Cell lines are used as it is more convenient than using a primary cell culture as it can be used over and over again for a certain period. But it is more prone to mutations and contaminations as their proliferation is increased.

What are the Similarities Between Primary Cell Culture and Cell Line?

• Both Cell Culture and Cell Line types of cells are used in research to study morphological, chemical and genetic characteristics of a cell.
• Both Cell Culture and Cell Line types of cells are extracted by mechanical and enzymatic methods.
• Both Cell Culture and Cell Line types of cells require growth media and specific growth conditions.
• Both Cell Culture and Cell Line types of cells are prone to mutations.

What is the Difference Between Primary Cell Culture and Cell Line?

Primary Cell Culture vs Cell Line
A primary cell culture is a culture prepared by direct isolation of cells by mechanical or enzymatic methods.	A cell line is prepared by continuously passaging a primary cell culture to obtain a cell line that has acquired homologous characters.
Number of Passages
Primary cell cultures are not passaged, cells are maintained under culture conditions.	Cells are passaged definitely or indefinitely in making cell lines.
Types
Adherent primary cell culture and Suspension primary cell culture are two types of primary cell cultures.	Finite cell line and continuous cell line are two types of cell lines.
Lifespan
Primary cell cultures have a short lifespan.	Cell lines have a longer lifespan.

Summary – Primary Cell Culture vs Cell Line

Primary cell cultures and cell lines are widely used in research to study the behavioural patterns of different cells under different conditions and under different pharmacological aspects. Primary cell cultures are directly isolated from the source organ or tissue and are grown on a culture media. The conditions are optimized for the growth of the specific cells. Cell lines, in contrast, are prepared by passaging the primary cell cultures for a finite or an infinite number of times. Cell lines are commercially available and are popular among researchers due to the ease of usage.

Reference:

1.Lonza, Primary Cells vs. Cell Lines. Available here

Image Courtesy:

1.’Human cell-line colony being cloned in vitro through use of cloning rings’ By Paphrag (CC BY-SA 2.5) via Commons Wikimedia