[1][2] Whereas western blot uses an antibody probe to detect a protein of interest, far-western blot uses a non-antibody probe which can bind the protein of interest.
In a western blot, specific proteins are then identified using an antibody probe.
In this way, binding partners of the probe (or the blotted) protein may be identified.
The probe protein is often produced in E. coli using an expression cloning vector.
Because cell extracts are usually completely denatured by boiling in detergent before gel electrophoresis, this approach is most useful for detecting interactions that do not require the native folded structure of the protein of interest.