Gibco™ Gentamicin (50 mg/mL)

Gentamicin is prepared in distilled water.

Spectrum: Gram positive and gram negative bacteria
Recommended concentration: 0.5 to 50μg/ml
Recommended storage condition: +15°C to +30°C


Use of Gentamicin
An ideal antibiotic for cell culture should have broad spectrum antibacterial and anti-mycoplasmal activity as well as freedom from cell toxicity.Gentamicin approaches these requirements. It has biological and biochemical properties, which render it superior to the use of Penicillin and Streptomycin (PS). In cell culture it is normally used at a concentration of 25-50μg/ml in growth medium but higher concentrations e.g. 200μg/ml are often used in viral studies when specimens are known to be infected.

Advantages
Broad Spectrum - wider and more effective than Penicillin/Streptomycin
As well as being active against many gram positive or gram negative organisms, Gentamicin is active against strains of Proteus and Staphylococcus which can sometimes be resistant to a PS mix and unlike PS, Gentamicin is active against Pseudomonas strains.

Anti-Mycoplasma Activity
Although not active against yeasts, moulds or protozoa, Gentamicin has been reported to be active against several but not all strains of mycoplasma.

pH Stability
Gentamicin has been shown to be stable over a pH range of 2 to 10 in Tissue Culture Media at +37°C for 15 days, unlike Streptomycin, which is rapidly destroyed by alkaline conditions and Penicillin, which is unstable at both acid and alkaline pH.

Temperature Stability
Gentamicin is stable at all temperatures and can withstand autoclaving. Thus if using autoclavable powder media, Gentamicin can be added before sterilisation. Normal autoclaving almost completely inactivates Penicillin and reduces the activity of Streptomycin by 50%.

Activity is unaffected by the presence of Serum
Compared with Pencillin, which immediately loses 30% of its activity when added to Tissue Culture Media containing serum, Gentamicin is unaffected.

Cell Tolerance
The suggested concentration is well below maximum dose tolerated by cells. Cells will tolerate in excess of 20X normal concentrations.

Stability and replication of Viruses in the presence of Gentamicin
The use of Gentamicin does not affect virus yields or plaque formation. In addition it does not affect interferon yields or assays.

Increased Virus Isolations
At present insufficient data is available to clearly demonstrate that this is the case but accumulating evidence seems to support this claim. Basically the reason is that the superior antibiotic activity of Gentamicin allows some badly infected cultures to grow and be read whereas less effective antibiotics would not control the bacterial growth and so the culture cannot be read.

Additional Use
As an additive in mycology media to prevent bacterial growth. The properties listed above make Gentamicin ideal for use in cell and tissue culture and also for transport of cell cultures and clinical specimens containing viruses or any specimens in which overgrowth by bacteria should be avoided.