Puromycin is an aminonucleoside antibiotic from Streptomyces alboniger. It is an analogon to aminoacyl-tRNA and inhibits the protein synthesis by termination of the peptidyl transfer at the ribosomes in prokaryotes and eukaryotes. The antibiotic inhibits the growth of gram positive bacteria and different animal cells. Fungi and gram negative bacterias are resistant, since puromycin cannot pass the cell wall. The discovery of the puromycin-N-acetyltransferase (PAC) in a Streptomyces-stem allowed to employ the antibiotic as a selection marker, comparable to neomycin. The working concentration is for mammalian cells depending on the cell line between 1 and 50 μg/ml.
Stock solutions of puromycin (10 mg/ml) can be prepared in HEPES buffer and are stored at +4°C or -20°C (improves stability) up to one year.