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
Synonyms: DSL-PMB; DSL-PMX; DSL-PxB
Storage: -20C
Application:
•Dansyl Labeled Polymyxin B Ready Made Solution (1.5 mg/mL) can be diluted 1:50 in PBSX1 (Sigma#D8537) to achieve 30 mug/mL final concentration for staining. The above concentration of DSL-PMB was used for E. coli staining see image.
•Fluorescence Microscopy application: Dansyl Labeled Polymyxin B Ready Made Solution excitation (Ex) wavelength is 330-340nm resulting with emission (Em) range of 540-600nm (lambdamax=570nm).Fluorescent antibiotics are obtained by synthetic conjugation of an antibiotic to a fluorophore. Fluorescent antibiotics can be used for many application including:
•Antimicrobial resistance research.
•Bacterial visualization and imaging.
•Parent antibiotic mode of action research and new antibiotic discovery.
•Toxicity studies.
•Research of bacterial infections and tracking its uptake in vivo.Additional possible applications for DSL-PMB:
•Can be applied as a fluorescent probe to study polymyxin mode of action and its pharmacokinetics.
•Research and develop new active derivatives of Polymyxin against multi-drug resistance gram negative infections.8
•Measure LPS binding affinity by fluorometric displacement assay.9-11