For interfacial studies, I would like to build an alanine scanning library for one of my proteins examining 20 sites. I will ultimately express the gene using E.coli cell-free protein synthesis. I already have the template gene which was originally built using PCR assembly. Now, what's the best way to build a scanning library?
The fastest will change as time passes and better technologies are developed.
I think the fastest method existing at the moment is Shotgun Mutagenesis (provided by Integral Molecular Inc).
This does not employ any new method of doing that. They just provide a set of plasmids, that has all the possible mutations. The set itself is generated by automated DNA synthesis.
So if you don't have a DNA synthesizer with you then simply order the kit from the company.