What is the Difference Between Migration and Invasion Assay

The main difference between migration and invasion assay is that migration assay determines the regular cell movement whereas invasion assays determine the migration of cells through the extracellular matrix. Furthermore, migration assays do not use a filter while invasion assays use a filter with molecules of the extracellular matrix (ECM), including collagen and elastin.  

Migration and invasion assays are two types of cell-based analysis methods of cell movements. Cell migration is a multi-step process important in the progression of various diseases including cancer, arthritis, and atherosclerosis while cell invasion encompasses the migration of cells through ECM degradation and proteolysis.

Key Areas Covered

1. What is a Migration Assay
     – Definition, Significance, Methods
2. What is an Invasion Assay
     – Definition, Significance, Methods
3. What are the Similarities Between Migration and Invasion Assay
     – Outline of Common features
4. What is the Difference Between Migration and Invasion Assay
     – Comparison of Key Differences

Key Terms

Chemotaxis Assays, Determination of Cell Movement, Extracellular Matrix, Invasion Assay, migration Assay

What is a Migration Assay

The migration assay is a method that determines the movement of cells in response to a particular chemical stimulus. Cell migration is a key property of living cells, and it is an important aspect in embryonic development or progression, developing immune responses, and several disease conditions including cancer metastasis, arthritis, atherosclerosis, and inflammation.

Figure 1: Agar Plate Technique

Furthermore, Agar-plate technique is an example of a migration assay. It uses a semi-solid matrix made up of either agar or gelatin through which the cells are supposed to migrate. Here, the cells and the target chemical substance can be placed separately in wells on the matrix. After the calibrated incubation time, the positive responder cells can be counted from the front of the migration direction. For instance, in the PP-technique, cells migrate through parallel channels made towards the target chemical substance. Here, cells have to move through 3 or more channels connected by a cut.

What is an Invasion Assay

The invasion assay is a more advanced method used to analyze cell migration. The most significant feature in these assays is the use of a filter which contains molecules of the extracellular matrix. These molecules can be collagen, elastin, etc.; hence, the filter represents the extracellular matrix. Two chamber techniques including the Boyden chamber, bridge chambers, and capillary techniques are examples of invasion assays.

Figure 2: Two-Chamber Techniques

Also, Boyden constructed the pioneer type of these chambers. In all methods, the filter mentioned above separates the two chambers. Here, one chamber contains the cells, and the other chamber contains the chemical substance. In addition to these methods, there is a wide range of protocols involved in the determination of the response of cells to the chemical stimuli.

Similarities Between Migration and Invasion Assay

• Migration and invasion assay are two analysis methods of different types of cell movements.
• They determine the movement of cells in response to a specific chemical stimulus.
• Both eukaryotic and prokaryotic cells can be tested with these.
• Also, both can provide either qualitative or quantitative measurements of cell movement.
• Furthermore, the determination of the incubation time is important in the quality control in both types of assays.
• Besides, both types of assays play a key role in drug discovery.

Difference Between Migration and Invasion Assay

Definition

Migration assay refers to the methods involved in the determination of cell movement due to a particular stimulus while invasion assay refers to the methods involved in the determination of cell movement through the extracellular matrix.  Thus, this is the main difference between migration and invasion assay.

Significance

Cell migration can be a multistep process while cell invasion is involved in ECM degradation and proteolysis. Hence, this is another difference between migration and invasion assay.

Use of a Filter

Use of a filter is another difference between migration and invasion assay. A filter is not used in migration assays while a filter with molecules of the ECM is used in invasion assays.

Examples

Agar-plate techniques are examples of migration assays while two-chamber techniques including Boyden chamber, bridge chambers, and capillary techniques are examples of invasion assays.

Conclusion

Both migration and invasion assays are chemotaxis assays which determine the movement of cells. Migration assay is an analysis method of cell movement in response to a particular chemical stimulus. In contrast, invasion assay is a more advanced analysis method of cell movement, which occurs through a filter with the molecules of the ECM including collagen and elastin. However, in migration assays, the movement of cells does not occur through such a filter.  Thus, the main difference between migration and invasion assay is the use of a filter, representing the ECM.

References:

1. “Chemotaxis Assay.” Wikipedia, Wikimedia Foundation, 25 Nov. 2018, Available Here
2. Justus, Calvin R et al. “In vitro cell migration and invasion assays” Journal of visualized experiments : JoVE ,88 51046. 1 Jun. 2014, doi:10.3791/51046

Image Courtesy:

1. “Chtx-asay-agar” By Kohidai,L – Own work (CC BY-SA 3.0) via Commons Wikimedia  
2. “Chtx-twochamber-techn” By Kohidai, L. – Own work (CC BY-SA 3.0) via Commons Wikimedia