Top : Molecular Biology : Transfection : Stable Transfection : G418 (Geneticin) Selection

Summary: G418 (Geneticin) Selection. G418 is an aminoglycoside antibiotic produced by Micromonospora rhodorangea. G418 blocks polypeptide synthesis by inhibiting the elongation step in both prokaryotic and eukaryotic cells. Resistance to G418 is conferred by the neo gene from Tn5 encoding an aminoglycoside 3'-phosphotransferase, APT 3' II. G418 is commonly used to select cells which have been transfected with a plasmid expressing the neo gene. In general, G418 concentrations of 400 mg/L are used for selection and 200 mg/L for maintenance for mammalian cells. However, optimal concentration for resistant clone selection in mammalian cells should be tested for a specific cell line. To do this, antibiotic titration is done using antibiotic concentrations ranging from 100 mg/L up to 1400 mg/L to determine the killing curve. Resistant clones selection may take 1 to 3 weeks.