Puromycin is used in cell biology as a 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 (50 mg/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 a selection agent in cell cultures is within a range of 1-10 μg/ml, although it can be toxic to eukaryotic cells at concentrations as low as 1 μg/ml. Puromycin acts quickly and can kill up to 99% of nonresistant cells within 2 days.
