What is the Difference Between Callus Culture and Suspension Culture

The key difference between callus culture and suspension culture is that callus culture is cultivated on an agar medium while suspension culture is cultivated in a liquid medium.

Callus culture and suspension culture are two types of cell cultures. Generally, a solid nutrient medium is used to prepare a callus. The callus is a mass of actively dividing cells. It shows as irregular shape and contains undifferentiated and unorganized cell mass. A liquid medium is used to prepare a suspension culture. As the name suggests, cells are suspended in a liquid medium and allow growing and multiplying. Both callus culture and suspension cultures are important in subculturing.  They are in vitro cultures. They require a good supply of nutrients as well.

CONTENTS

1. Overview and Key Difference
2. What is a Callus Culture  
3. What is a Suspension Culture
4. Similarities – Callus Culture and Suspension Culture
5. Callus Culture vs Suspension Culture in Tabular Form
6. Summary – Callus Culture vs Suspension Culture

What is a Callus Culture?

Callus culture is an irregular, undifferentiated and unorganized mass of dividing cells cultivated on an agar medium supplemented with plant growth regulators. In the plant tissue culture, a piece of plant tissue from the explant should be placed on a nutrient medium to obtain a callus. In order to regenerate a plant, this callus should be transferred to a different medium. A callus culture undergoes three stages as induction, proliferation, and differentiation. Generally, callus cells are parenchyma cells. In plants, callus growth can be seen in plant wounds.

Plant callus cultures relatively contain high levels of auxin and cytokinins. Sometimes callus cultures are prepared to extract bioactive compounds. Therefore, they are harvested at a specific stage, dried, and the compounds are extracted. Generally, the stationary phase is the specific stage that is the most suitable phase to collect callus due to the high production of secondary metabolites during the stationary phase.

What is a Suspension Culture?

Suspension culture is a type of cell culture grown in a liquid medium. Single cells or aggregates of cells are suspended in a liquid medium for growth. Within a few days, the cell density of the suspension comes to the optimal level.

It is very important to agitate the suspension culture continuously to mix the content and to aerate the culture. Moreover, growth conditions and nutrient levels should be maintained all the time. In addition, continuous monitoring of the process is necessary till the growth is completed.

What are the Similarities Between Callus Culture and Suspension Culture?

• Callus culture and suspension culture are two types of cell culture grown in laboratories for research purposes.
• They are sub-culturing techniques.
• They are in vitro.
• A good nutrient supply is necessary for both cultures.

What is the Difference Between Callus Culture and Suspension Culture?

Callus culture is an undifferentiated, unorganized mass of dividing cells grown on an agar medium, while suspension culture is a liquid culture in which single cells or a group of cells are suspended. So, this is the key difference between callus culture and suspension culture. Moreover, suspension cultures are agitated continuously, while callus cultures are not agitated.

The following figure presents the difference between callus culture and suspension culture in more detail.

Summary – Callus Culture vs Suspension Culture

Callus culture and suspension culture are two culturing techniques. Their applications depend on the purpose of culturing. Callus culture is a mass of cells that are undifferentiated, unorganized, and actively dividing. In plant tissue culture, plant calli are grown in order to regenerate plants. Plant calli also facilitate the amplification of limiting plant material. Suspension culture is a liquid culture in which cells are suspended. Suspension culture grows faster than callus culture, which takes two to three weeks. Moreover, suspension cultures should be agitated continuously, while agitation is not applicable to callus cultures. Thus, this is the summary of the difference between callus culture and suspension culture.

Reference:

1. “Overview of Callus and Organ Culture!” Plant Cell Technology, 15 June 2021.
2. “Callus Culture.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Callus1” By Igge – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Synechococcus cyanobacteria-cultures” By Masur – Own work (Public Domain) via Commons Wikimedia