Microplate Sealing Equipment
Sigma Aldrich Fine Chemicals Biosciences Dansyl labeled polymyxin B
Dansyl Polymyxin B (DSL-PMB) is a fluorescent derivative of Polymyxin B. Its mode of action is in accordance to Polymyxin B activity. However MIC assays comparing DSL-PMB and parent Polymyxin B showed two to three-fold decrease in bacterial activity.1 2Polymyxin B is a cationic lipopeptide antibiotic which binds specifically to gram negative bacteria.3-6 It interacts with anionic lipopolysaccharide (LPS) molecules which are located in gram negative bacterial outer membrane.7 This interaction interferes with the outer membrane normal function causing leakage and enhanced uptake of the antibiotic.7 Resemblance in properties between Polymyxin B and DSL-PMB allows to fluorescently label gram negative bacteria and examine intracellular localization and penetration of Polymyxins in gram negative bacteria.2 8
