Aminoglycoside antibiotic inhibits growth of prokaryotic (bacteria), eukaryotic microorganism (yeasts) and mammalian cells. Particularly useful as a selective agent for the incorporation of the APH 4 gene in plant tissue. Inhibits peptide chain elongation by preventing elongation-factor EF-2 dependent translocation. Supplied as 1 million units in solution per vial. 1 Million Units of Hygromycin B equals approximately 1 gram of lypholized Hygromycin B powder.