Polymyxin B Sulfate is a cyclic polycationic peptide antibiotic that binds to anionic lipids. It is also a selective inhibitor of protein kinase C. Other direct and indirect biological effects of polymyxin B include induction of apoptosis, blocking the effect of endotoxins, modulation of K+-ATP channels, inhibition of the effect of phorbol ester–stimulated superoxide release, inhibition of sarcoplasmic reticulum Ca2+-ATPase, and inhibition of insulin secretion. Polymyxin B is also reported to be a potent inhibitor of calmodulin (C23693), with an IC50 of 80 nM in the presence of 500 µM Ca2+.

USP grade, nonsterile, crystalline

Keep your irreplaceable cultures contamination free

Researchers are typically concerned about two types of cell culture contamination: the contamination of cell cultures with microbiological organisms and the contamination of one cell line with another. Both types of contamination are extremely prevalent, and the possibility of contamination—and the impact on results—cannot be underestimated. The decision to use antibiotics and antimycotics to prevent contamination should be based on the individual researcher’s needs and experience.

We manufacture a wide array of antibiotics and antimycotics to control contamination arising from bacteria, fungi, mycoplasma, and yeast. While researchers may attempt to eliminate or control contaminations with antibiotics or antimycotics, it should be noted that these substances can be toxic to certain cell lines. Before using, it is essential to first perform a dose-response test to determine the level at which toxicity begins.