Puromycin

Puromycin is an antibiotic that is a potent inhibitor of translation.

Inhibition of translation
Puromycin is an aminonucleoside antibiotic, derived from the Streptomyces alboniger bacterium, that causes premature chain termination during translation taking place in the ribosome. Part of the molecule resembles the 3' end of the aminoacylated tRNA. It enters the A site and transfer to the growing chain, causing premature chain release. The exact mechanism of action is unknown at this time, but, the 3' position contains an amide linkage instead of the normal ester linkage of tRNA, the amide bond makes the molecule much more resistant to hydrolysis and thus causes the ribosome to become stopped.

It is not selective for either prokaryotes or eukaryotes.

Also of note, puromycin is critical in mRNA display as it allows the growing peptide chain to be covalently bonded to its own mRNA template.

Cell culture
Puromycin is used in cell biology as selective agent in cell culture systems. It is toxic to prokaryotic and eukaryotic cells. Resistance to puromycin is conferred by the Pac gene encoding a puromycin N-acetyl-transferase (PAC) that was found in a Streptomyces producer strain. Puromycin is soluble in water (50mg/ml) as colorless solution at 10 mg/ml. Puromycin is stable for one year as solution when stored at -20°C. The recommended dose as selection agent in cell culture is at a range of 10-100 μg/ml, although it can be toxic to eukaryotic cells at concentrations as low as 1 μg/ml. It acts quickly and can kill up to 99% of nonresistant cells within 2 days