Rifampicin

Mode of Action

Strongly inhibits prokaryotic RNA polymerase and mammalian RNA polymerase to a lesser degree. Does not inhibit T7 RNA polymerase.

Mechanism of Resistance

Cells can spontaneously mutate to achieve resistance to Rifampicin.

Usage Notes

1. 50 mg/mL stock solution in methanol.
2. Vortex immediately to prevent rifampicin from sticking to bottom of tube.
3. Add ~5 drops 10 N NaOH per mL to facilitate dissolving.
4. Add 2 mL per liter of culture to achieve a working concentration of 100 μg/mL.

Rifampicin is light-sensitive so store stock solution, plates and media in the dark and wrap in foil.

References

• A Short Course in Bacterial Genetics
• Molecular Cloning