Difference Between Adherent and Suspension Cells

The key difference between adherent and suspension cells is that the adherent cells need solid support for their growth while the suspension cells do not need solid support for the growth.

A cell is the basic structural and functional unit of an organism. Various research projects require the preparation of cell cultures. Cancer cells, hepatocytes, kidney cells and various microbial cells are some of the common cells that use in cell culturing. In all cell culturing processes, it is necessary to have a primary cell culture to make the cell lines. When preparing cell cultures, cells exist in two forms either as adherent cells or as suspension cells. In adherent cells, primary culture cells need solid support to attache. Therefore, they are anchorage-dependent cells. But in suspension cells, primary culture cells do not need solid support to attach. They submerge in the liquid media. Hence, they are not anchorage dependent. In overall, the key difference between adherent and suspension cells is the anchorage dependence of the cells.

CONTENTS

1. Overview and Key Difference
2. What are Adherent Cells
3. What are Suspension Cells
4. Similarities Between Adherent and Suspension Cells
5. Side by Side Comparison – Adherent vs Suspension Cells in Tabular Form
6. Summary

What are Adherent Cells?

Adherent cell lines are the cells that are anchorage dependent. Therefore, these cells require stable support, which is called adherent, for their growth. Most of the cells derived from vertebrate cells (except hematopoietic cells) are anchorage dependent. Therefore, maintenance of most of the vertebrate cells requires an adherent that yields a steady growth of those cells.

Most of the adherent cell lines established in tissue culture treated vessels. Hence, their growth always restricts to the area of the vessel or the adherent. When preparing adherent cell lines, the adherent cells must be trypsinized. And also, repeated passaging of the cells is done before preparing an adherent cell line. Adherent cell lines are valuable in cytogenetics and in different research projects.

What are Suspension Cells?

Suspension cells are anchorage independent. Hence, these cells can readily grow suspended in a liquid medium. In order to provide optimum conditions for their growth, it is necessary to mix the medium continuously by agitation. Human hematopoietic cells are one of the suspension cell cultures prepare commonly in laboratories. This is due to the fact that they don’t need any solid support to attaché for their growth.

Maintenance of suspension cells requires continuous agitation and few passaging procedures. Most importantly, the concentration of the nutrients in the medium restricts the growth of cells in the medium. Thus, over time, the growth factors and media constituents deplete limiting the growth of the cells. Therefore it is utmost important to maintain all the requirements at an optimum level in order to achieve a proper growth of the suspension cells.

In commercial applications, suspension cells are the most widely used type of primary cell lines. In both continuous and batch fermentations, an active suspension cell culture acts as a starting culture. Furthermore, suspension cell cultures yield much higher products than the adherent cell lines. Another advantage of suspension cells over adherent cells is that the preparation of suspension cells is less laborious and requires less expenditure in comparison to adherent cells. Therefore, the production of secondary metabolites such as antibiotics, vitamins, amino acids, proteins, etc., can be easily done by suspension cell cultures.

What are the Similarities Between Adherent and Suspension Cells?

• Adherent and Suspension Cells are two types of cells that derive from primary cell cultures.
• Both require optimum media conditions and growth conditions to achieve maximum
• Both are prepared under in vitro conditions and can be stored under special storage conditions.
• They require continuous passaging to increase the yield.
• They have a use in research and experimental purposes.
• Both cells can be transformed into their respective cell lines.

What is the Difference Between Adherent and Suspension Cells?

Adherent cells, as the name implies, grow attached to a surface. In contrast, suspension cells grow in a liquid medium without attaching to a surface. This is the main difference between adherent and suspension cells. Furthermore, the growth of adherent cells limits only into the surface area of the adherent while, for the suspension cells, there is no such restriction. However, many factors such as aeration, constituents of the medium, temperature, pH etc. limit the growth of suspension cells.

The following infographic provides more facts about the difference between adherent and suspension cells,

Summary – Adherent vs Suspension Cells

When we grow primary cells in a liquid medium, it becomes a suspension cell culture. In opposite to that, when we allow primary cells to attach into a solid surface and grow, it becomes an adherent cell culture. This is the main difference between adherent and suspension cells. So the adherent cells are anchorage-dependent while the suspension cells are anchorage independent. Furthermore, the maintenance of suspension cells requires a continuous agitation of the medium, unlike in adherent cells. However, both adherent and suspension cells can convert into cell lines, which are useful in research purposes and in cell culture studies.

Reference:

1.“Adherent Cell Culture vs. Suspension Cell Culture.” Thermo Fisher Scientific – LK. Available here  
2.“Outgrown the Roost: Passaging Suspension Cells.” Bitesize Bio, 6 Feb. 2013. Available here

Image Courtesy:

1.”Cho cells adherend1″By User:Alcibiades – Own work, (Public Domain) via Commons Wikimedia  
2.”Penicillin bioreactor”By Matt Brown – Flickr, (CC BY 2.0) via Commons Wikimedia