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phage display - peptide differentiation (Jul/27/2010 )

I don't know if this is the right forum, and in case it isn't sorry and please direct me to the right one...

I'm working with phage display libraries from NEB. I want to find a non destructive way of differentiation between/grouping peptides from a sample. Each phage has between 3-5 identical peptides displayed on its coat protein. Each sample (0,5-1 ml of eluted phage) contains 10^2-10^4 (estimate) phage particles, where the phage part is the same, only difference is the peptide. There could be up to ~50 clones of each peptides-specific phage.
Any ideas as how to do this?


Hi Chaim,

I am guessing that you got your information already, but anyway. There is absolutely no way to do this. The whole point of biopanning is to enrich for clones that have higher affinities for the target than phage you wash away. With the libraries you are using there are usually closer to 10^7 pfu/ml of eluate. After the first round of panning you only have a few copies of each phage clone. When you amplify the phage you increase the number of copies for the next round of selection. Even after three or four rounds of panning you have between a couple of thousand and a couple of hundred thousand copies of each clone. Even if there were a way of grouping them according to their expressed peptides, these numbers are so low, that there is absolutely no way of visualizing them.
I am sorry that it isn't easier, but it is what it is. Best of luck.