G418 disulfate, also known as geneticin, is similar in structure to gentamycin B1 and is an aminoglycoside antibiotic commonly used in plant and mammalian cell culture as a selectable marker. Aminoglycosides target the 30S ribosomal subunit resulting in an inability to read mRNA ultimately producing a faulty or nonexistent protein. G4148 disulfate is freely soluble in water.
G418 can be used to screen for plants which have been transformed with resistance plasmids containing the nptII gene. The npt II gene encodes aminoglycoside 3'-phosphotransferase; a kinase which inactivates a number of antibiotics including paromomycin, G418, and kanamycin.
G418 is routinely used in gene selections to screen for resistant mammalian cells which express the neo gene. The neo gene encodes amino-glycoside 3’-phosphotransferase; an enzyme which renders the cell resistant to G418. For gene selection applications, a kill curve can be made to determine the minimum effective G418 concentration to kill non-resistant cells.
TESTED AGAINST BOTH SENSITIVE AND RESISTANT CELLS AT GOLD BIOTECHNOLOGY LAB.
