PHAGE DISPLAY EXPLAINED (2 Minutes)

Phage display is a technique used in the study of protein interactions using bacteriophages, or viruses that infect bacteria. It works by inserting the gene encoding our protein of interest into a bacteriophage, causing it to express the protein on its surface, while simultaneously maintaining the gene inside of it. This results in a connection between the genotype and the phenotype of the protein of interest.

Here's a simplified explanation of how a phage display protocol may be carried out:

1. A library of bacteriophages is created, by adding the genes coding for different proteins to each of the phages, causing them to express said proteins on top of them as a sort of protein hat.
2. This library of bacteriophages are exposed to selected targets. Only some bacteriophages will interact with the specific ligands on these targets, subsequently attaching themselves to them.
3. All unbound bacteriophages are washed away. Only bacteriophages expressing proteins, displaying affinity to the selected targets will remain.
4. The remaining bacteriophages are recovered through an elution step, such as for example affinity chromatography.
5. These recovered bacteriophages can then be used to infect new host cells for amplification.

Finally, this 5-step cycle is repeated 2-3 times to increase the affinity between the expressed proteins and the selected targets.


Phage display is used in a wide range of applications, including drug discovery, vaccine development, and protein engineering. It is a powerful tool for identifying and isolating specific proteins or peptides from complex mixtures.