Neomycin Phosphotransferase - G418 Resistance - Normal mammalian cells are sensitive to the aminoglycoside antibiotic 0418, which inhibits protein synthesis. Neomycin phosphotransferase encoded by the bacterial transposons Tn5 and Tn601 confer resistance to G418.

Transfected cells are efficiently selected for on a medium containing the antibiotic G418, which is a powerful selection agent.In conclusion, scorable reporter genes are used in studies on promoter/ enhancer functions etc., and are of little direct utility in the selection of transfected cells for which selectable reporter genes have been developed.