The main difference between monolayer and suspension culture is that monolayer culture is an anchorage-dependent culture whereas suspension culture is an anchorage-independent culture. Therefore, the cells of the monolayer culture grow attached to the surface of the flask while the cells of the suspension culture mainly grow floating in the medium.
Monolayer and suspension culture are two types of animal cell cultures classified based on the type of cell growth.
Key Areas Covered
1. What is a Monolayer Culture
– Definition, Features, Importance
2. What is a Suspension Culture
– Definition, Features, Importance
3. What are the Similarities Between Monolayer and Suspension Culture
– Outline of Common Features
4. What is the Difference Between Monolayer and Suspension Culture
– Comparison of Key Differences
Key Terms
Anchorage, Harvesting, Monolayer Culture, Passaging, Suspension Culture, Substrate
What is a Monolayer Culture
Monolayer culture or adherent culture is a type of animal cell culture in which the growth of cells occurs attached to the surface of the flask. Therefore, it is anchorage-dependent. Also, these cells require a substrate for their growth. Moreover, the charged surfaces promote the cell to cell interactions. Generally, most animal cells that are immobile grow in an anchorage-dependent manner. Therefore, all vertebrate cells excluding the cells of the hematopoietic lineage have to grow in monolayer cultures.
Figure 2: Blood Culture
Furthermore, most primary cell cultures are also monolayer cultures. The cells of a monolayer culture can be harvested either through mechanical or enzymatic degradation. However, the surface area of the flask can be a limiting factor for cell growth in this type of cell cultures. The reduced surface area may limit the product yield.
What is a Suspension Culture
Suspension culture is another type of animal cell culture in which the cells are floating in the medium. Here, these cells may form floating aggregates. However, some cells may adhere to the flask lightly. Thus, suspension cultures do not require a substrate for the attachment. Furthermore, some animal cells are anchorage-independent including the cells of the hematopoietic lineage. Therefore, they can be grown in suspension cultures. Although these cells do not require a substrate, it requires continuous agitation for adequate gas exchange.
Figure 1: Adherend Chinese Hamster Ovary (CHO) Cells in Cell Culture Flask
However, the main limiting factor for cell growth in suspension culture is the concentration of cells. Here, the appropriate dilution of the sample may increase cell growth. In contrast, the harvesting is easy in suspension culture as the cells are in the medium. It can be done by centrifugation. The passaging or the subculturing of a suspension culture can be done by diluting a small portion of the culture in a large volume of fresh culture.
Similarities Between Monolayer and Suspension Culture
- These are two types of animal cell cultures.
- And, both are classified based on the type of cell growth.
Difference Between Monolayer and Suspension Culture
Definition
Monolayer culture refers to a type of culture in which cells are grown in a single layer on a flask or Petri dish containing the culture medium while suspension culture refers to a type of culture in which single cells or small aggregates of cells multiply while suspended in an agitated liquid medium.
Degree of Anchorage
Thus, the main difference between monolayer and suspension culture is that monolayer culture is anchorage-dependent whereas suspension culture is anchorage-independent.
Requirement of a Substrate
The cells of a monolayer culture require a substrate for attachment while the cells of a suspension culture do not require a substrate for attachment. Hence, this is also an important difference between monolayer and suspension culture.
Method of Cell Growth
Furthermore, the cells of the monolayer culture grow attached to the surface of the flask while the cells of the suspension culture mainly grow floating in the medium.
Appropriate for
Also, monolayer cultures can be appropriated for most types of cells and for primary cultures while suspension cultures can be appropriated for the cell lines that are not adhesive such as hematopoietic cell lines.
Type of Vessels
Another difference between monolayer and suspension culture is that the monolayer cultures require tissue-culture treated vessels while suspension cultures do not require tissue-culture treated vessels.
Inspection
Besides, monolayer culture can be visually inspected easily via the inverted microscope while daily counts are required for the determination of viability and growth patterns in suspension culture.
Limitation of the Growth
Moreover, the surface area limits the growth of a monolayer culture while the concentration of cells in the medium limits the growth of suspension culture. So, this is also a difference between monolayer and suspension culture.
Growth Control
Additionally, contact inhibition can control the growth of a monolayer culture whereas density limitation can control the growth of a suspension culture.
Passaging/Sub Culturing
One other difference between monolayer and suspension culture is that the monolayer cultures require periodic passaging while the suspension cultures are easy to passage.
Harvesting
Furthermore, it is possible to dissociate the cells of a monolayer culture either enzymatically or mechanically whereas a suspension culture does not require such dissociation.
Uses
Considering the uses, monolayer cultures are used in cytology, for harvesting products continuously, and many research applications while suspension cultures are used bulk protein production, batch harvesting, and many research applications.
Conclusion
Monolayer culture is a type of animal cell culture in which the cells grow attached to the surface of the flask. Therefore, it is a type of anchorage-dependent cell culture. Most animal cells are anchorage-dependent. However, the surface area of the flask can be a limiting factor for growth. In contrast, suspension culture is another type of animal cell culture in which cells grow by floating in the medium. Therefore, it is a type of anchorage-independent cell culture. Generally, the cells of the hematopoietic lineage are anchorage-independent. Here, the concentration of the cells in the medium can be a limiting factor. Hence, the main difference between monolayer and suspension culture is the method of cell growth in the medium.
References:
1. “Adherent Cell Culture vs. Suspension Cell Culture.” Thermo Fisher Scientific – US, Available Here.
Image Courtesy:
1. “Cho cells adherend2” By User:Alcibiades – Self-made during work (Public Domain) via Commons Wikimedia
2. “Blutkultur – blood culture” By Strolch1983 – Own work (CC BY-SA 3.0) via Commons Wikimedia
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