Blasticidin S (BS)

Blasticidin S is an antibiotic that is produced by Streptomyces griseochromogenes. In biological research, specifically genetic engineering, it is used to select transformed cells which have been engineered to carry a resistance gene for blasticidin. In short, DNA of interest is fused to DNA encoding a resistance gene, and then is transformed into cells. After allowing time for recovery and for cells to begin transcribing and translating their new DNA, blasticidin is added. Now only the cells that have the new DNA can grow.

Blasticidin prevents the growth of both eukaryotic and prokaryotic cells. It works by inhibiting termination step of translation and peptide bond formation (to lesser extent) by the ribosome. This means that cells can no longer produce new proteins through translation of mRNA.