The fishing can be done in several ways, depending on the target of interest and how it can be recombinantly produced (or not). For instance, you can interrogate your library of phages for selection on solid phase (where the antigen is coated on a plate), or in solution (where the antigen is coupled to beads). If you're antigen is difficult to produce (for instance a GPCR), you could select in solution on recombinant CHO or HEK cells expressing the target (allowing proper folding of the target). Furthermore, selection strategies can be designed for diversity, or for affinity, all depending on the goal of the discovery strategy. Informative introductory video on Phage Display! Cheers
This could be what was used to generate the 100x higher-binding-affinity ACE2 RBD in Covid-19. Such high binding affinity have never been found in nature for betacoronaviruses in general.
The antibody is displayed on the phage coat, which is outside of the phage capsule. The phage structure is built by the host bacteria. If we insert the gene encoding the desired antibody inside the coding region for the phage coat, the antibody will be expressed on the coat when the host bacteria replicates the phage.
@@scottcampbell6390 yeah so because we cannot rely on the bacterias ability to correctly fold an eukaryotic molecule one has to consider that this molecule could differ in structure from what would be achieved in an eukaryotic cell using the same gene right?
Excellent explanation and animation! It's also used to 'fish' for Nanobodies! If you don't know what Nanobodies are, I made an introductory video on my channel. Great video, Charlie Abbott!
Would this be useful to other protein expression platforms, say in plants such as tobacco? And if you wanted to make a unique antibody that you didn't have the antigen for how could you go about that...? Thanks for the video was very helpful :)
Well, you could trigger an immune response in mice by injecting a human target, then you isolate the B-cells from the mouse, and then you extract the RNA from those B-cells, and you got yourself a library :)
