G418 Selective Antibiotic, Sterile 

G418 selective antibiotic is an aminoglycoside antibiotic produced by Micromonospora rhodorangea. It acts by binding to the 80S subunit of the bacterial ribosome, thus inhibiting protein synthesis in both prokaryotic and eukaryotic cells.

Resistance to G418 selective antibiotic is conferred by the E. coli APH (3) I and APH (3) II resistance genes. The gene becomes APH (3) II on Tn5 and APH (3) I on Tn601. Therefore, G-418 selective antibiotic can be used to select and maintain prokaryotic or eukaryotic cells carrying the G418 resistance gene.

-20°C; 2 years.

1. The working concentration of G418 selective antibiotic varies with cell type, media, growth conditions and cell metabolic rate.

2. Before stable transfected cell lines can be selected, the optimal G418 selective antibiotic concentration needs to be determined by performing a kill curve titration.

1) Seed the parental cell line in a suitable culture plate at a cell density of 20-25% and incubate the cells for 24 hours at 37°C.

2) Remove medium and then add medium with various concentrations of G418 selective antibiotic (such as 0, 50, 100, 200, 400, 800, and 1000 μg/mL) and incubate at 37°C.

3) Refresh the selective medium every 2-3 days and observe the percentage of surviving cells over time.

4) Determine the lowest concentration of antibiotic that kills a large majority of the cells within 14 days. This concentration should be used for selection of a stable transfected cell line.