One protein is immobilized on resin via a fused affinity tag. The second protein is incubated with the resin. Proteins are detected either by silver staining or by Western blotting. Elevated reporter gene activity is taken as evidence that protein X and Y interact. But the assay is typically run in yeast.
Techniques exist that allow genes to be knocked of the genome of many of the model organisms .
Mouse knockouts are used widely as proxies for human diseases. Anti-sense technology uses synthetic DNA or expressed RNA that is complimentary to the mRNA to inhibit gene function. The antisense RNA hybridizes to the 'sense' strand and prevents it from being translated .