Polymyxin B Solution w/ 50mg/ml Polymyxin B in sterile tissue culture grade water Suitable for vaccine production

Polymyxin B sulfate, a polypeptide antibiotic, is the sulfate salt of polymyxin B1 and B2 produced by the growth of Bacillus polymyxa. They are basic polypeptides of about eight amino acids and have cationic detergent action on the cell membrane. Polymyxin B sulfate has bactericidal action against Gram- negative bacteria. It alters the cytoplasmic permeability by binding to negatively charged site in the lipopolysaccharide layer which has electrostatic attraction for the positively charged amino groups in the cyclic peptide portion. International unit of polymyxin B is defined as the activity contained in 0.000119mg of the second International Standard (1969) of polymyxin B sulfate which contains 8403 units per mg. In cell culture, polymyxin B sulfate is used as an anti-bacterial agent to prevent contamination.