Neomycin sulfate is an aminoglycoside antibiotic produced by S. fradiae that inhibits protein translation by binding to the small subunit of prokaryotic ribosomes. It blocks voltage-sensitive Ca2+ channels and is a potent inhibitor of skeletal muscle sarcoplasmic reticulum Ca2+ release. NEOMYCIN SULFATE has been shown to inhibit inositol phospholipid turnover, phospholipase C, and phosphatidylcholine-phospholipase D activity (IC50 = 65 μM). It is highly effective against Gram-positive and Gram-negative bacteria and is commonly used for the prevention of bacterial contamination of cell cultures.