G 418, or Geneticin, is an aminoglycoside antibiotic from Micromonospora rhodorangea. The antibiotic is used for the selection and maintenance of eukaryotic cells expressing the neomycin resistance gene (neo). G 418 blocks polypeptide synthesis by inhibiting the elongation step. It is similar in structure to gentamycin B1 but active against both bacteria and eukaryotes.Stock solution, for cell culture, biochemistry, and molecular biology. Formulated to contain 50 mg/ml G 418 base in deionized water. 50 mg G 418 base are approx. 70 mg G 418 sulfate (based on dry weight). The working concentration has to be established for every cell type. Bacteria and algae require 5 µg/ml or less while animal cells may require 300 - 500 µg/ml. G 418, or Geneticin, is an aminoglycoside antibiotic from Micromonospora rhodorangea. The antibiotic is used for the selection and maintenance of eukaryotic cells expressing the neomycin resistance gene (neo). G 418 blocks polypeptide synthesis by inhibiting the elongation step. It is similar in structure to gentamycin B1 but active against both bacteria and eukaryotes.Stock solution, for cell culture, biochemistry, and molecular biology. Formulated to contain 50 mg/ml G 418 base in deionized water. 50 mg G 418 base are approx. 70 mg G 418 sulfate (based on dry weight). The working concentration has to be established for every cell type. Bacteria and algae require 5 µg/ml or less while animal cells may require 300 - 500 µg/ml.