G418 Disulfate (Low Endotoxin)

- Overview
  - G418 Disulfate (Low Endotoxin) has a strict endotoxin content of ≤ 1 EU/mg. G418 Disulfate, an aminoglycoside antibiotic originally isolated from Micromonospora rhodorangea, is routinely used for gene selection in cell culture. The presence of endotoxin in G418 Disulfate can decrease transfection efficiency and even be toxic to resistant eukaryotic cells.
    
    Please contact us at for specific academic pricing.
    
    Background
    
    G418 Disulfate, along with other aminoglycosides, prevent protein synthesis. Resistance to G418 Disulfate is conferred by the neo gene (neomycin resistant gene) from either Tn5 or Tn601 (903) transposons. Cells successfully transfected with resistance plasmids containing the neo resistance gene can express aminoglycoside 3'-phosphotransferase (APT 3' I or APT 3' II) which covalently modifies G418 to 3-phosphoric G418, which has negligible potency and has low-affinity for prokaryotic and eukaryotic ribosomes.
- Properties
  - CAS Number
    
    108321-42-2
    
    Molecular Formula
    
    C20H40N4O10 · 2 H2SO4
    
    Molecular Weight
    
    692.71
    
    Appearance
    
    White or off-white powder
    
    Solubility
    
    (100mg/mL in H20): Clear and complete
    
    Storage
    
    ≤30 °C
    
    * For research use only
- Applications
  - Application Description
    
    Spectrum: G418 Disulfate is toxic to susceptible prokaryotic and eukaryotic cells including fungi (yeasts and molds), bacteria, mammalian and plant cells.
    
    Microbiology Applications: G418 Disulfate can be used as a selection agent for G418 resistant bacteria or fungi after transformation.
    
    Eukaryotic Cell Culture Applications: G418 Disulfate is routinely used as a selection agent in cell culture after transfection of eukaryotic cells. Resistant cells express the neo gene which produces aminoglycoside 3'-phosphotransferase (APT 3' I or APT 3' II), a protein that confers resistance to G418 Disulfate and other aminoglycoside antibiotics.
    Optimal working concentrations:
    
    Mammalian cell lines: 200 mg/L – 1000 mg/L
    Bacteria and algae: ≤5 mg/L
    
    The optimal working concentration of G418 sulfate to select for resistant clones depends on the cell line, reagent quality, reagent lot, media, growth conditions, cell density, cell metabolic rate, cell cycle phase, and plasmid quality. A kill curve should be performed to determine the optimal concentration for each experimental system.
    Use the following guide to determine the concentration to use to generate a kill curve:
    
    5 mg/L - 1400 mg/L (mammalian cells)
    0.1 mg/L - 50 mg/L (bacteria and algae)
    
    A working concentration of 200 mg/L is usually sufficient after resistant mammalian clones are selected and can be used for maintenance until stable resistant clones are selected.
    High quality G418 Disulfate has high potency against sensitive cells (low ED50 concentration) and low potency against transfected resistant cells (high ED50 concentration). Impurities and certain bioactive substances such as endotoxins can be toxic.
    For more information on relevant cell lines, culture medium, and working concentrations, please visit the TOKU-E Cell-culture Database.