Cell Strain And Cell Line

In scientific research related to life sciences, the two terms cell strain and cell line are often heard. For many students who are new to the field, these terms are often confusing. In this issue, we will briefly introduce the differences and connections between these two terms.

Hela cell strain

Origin of the Terms

The term “cell strain” was first used by W. Earle in 1940. He referred to the L strain of mouse connective tissue he established as a “strain”. In 1954, White used the term “line” to refer to the group of chick embryo heart cells cultured by A. Carrel. This marked the origin of the term “cell line”.

 

01. Cell Line.

Before introducing the concept of cell lines, let’s look at another term—primary cells. Primary cells refer to individual cells obtained from animal or plant tissues or organs through chemical or mechanical treatment and then cultured in vitro to simulate in vivo conditions. Primary cells grow slowly and have a limited lifespan. Generally, they can only be passaged for about 10 generations, after which they show growth arrest and a large number of cells undergo senescence and die.

 

With the concept of primary cells in mind, the concept of cell lines becomes easier to understand.

 

A cell line refers to a group of cells that has been formed by successful subculturing of primary cells. It generally refers to cells capable of being passaged. If the cells cannot continue to be passaged or have a limited number of passages, they are called finite cell lines or established cell lines. If the cells can be continuously subcultured, they are called continuous cell lines or immortalized cell lines, capable of being cultured beyond 50 generations indefinitely.

 

MH7A rheumatoid arthritis synovial fibroblast cell line

02. Cell Strain

A cell strain refers to a cell population obtained from a biologically identified cell line or primary culture through single-cell isolation or screening methods (such as selection or cloning), in which the single cell with special characteristics or markers is cloned. It can also be simply understood that a cell strain is a group of cells with specific properties selected from a cell line.

 

The special properties or markers of a cell strain must persist throughout the entire culture period.

 

In terms of passage number, it can generally be cultured for 40–50 generations. If it cannot be continuously passaged or has limited passages, it is called a finite cell strain. If it can be continuously passaged, it is called a continuous cell strain. If a new cell group with different characteristics is isolated from the original strain, it is called a sub-strain. A clone is a special case of a cell strain and refers to a population of cells derived from the proliferation of a single cell.

 

BMDM primary cells

 

When culturing cells in vitro, it is necessary to simulate the growth environment of the organism. In addition to providing essential nutrients for growth, external conditions such as CO₂ concentration, temperature, humidity, and rotational speed for suspension cells must also be ensured.

 

Our company has always been committed to the independent development of external environments required for cell culture—cell incubators and cell shaker incubators. Feel free to contact us for more information.