Blasticidin S is an aminoacylnucleoside antibiotic isolated from Streptomyces griseochromogenes. It shows high efficacy against both eukaryotic and prokaryotic cells. Aside from its antimicrobial properties, blasticidin has displayed antiviral, antitumor, and antifungal properties and has been used as a selection agent. It has been used to select for cells containing the bls, bsr, or BSD resistance gene as well as HEK293-T cells and HEK-D5 cells. Additionally, blasticidin is effective in preventing cell culture contamination and studying protein synthesis.

Blasticidin S functions by inhibiting peptide bond formation at the ribosome. It blocks hydrolysis of peptidyl-tRNA due to the large ribosomal subunit's increased affinity for tRNA.

Antibiotics are often used in clinical in vitro tests known as antimicrobial susceptibility tests or ASTs to determine their efficacy against certain bacterial species. They are tested against gram-negative and gram-positive bacteria using panels, discs, and MIC strips by medical microbiologists. ASTs decrease the risk of using an antibiotic against bacteria exhibiting resistance to it, and the results are used in clinical settings to determine which antibiotic(s) to prescribe for various infections.