Application

Filipin has been used in a double staining procedure as a probe for the detection of lipoproteins in polyacrylamide gel and immobilized on nitrocellulose membranes. It is also widely used to localize and quantitate unesterified cholesterol by virtue of a specific fluorescent complex.

General description

Filipin III is a polyene macrolide antibiotic and the major component isolated from cultures of S. filipinensis. ¹ Due to its ability to fluoresce and bind to cholesterol, Filipin has been widelyused as a probe for sterol location in biological membranes ² and has been used clinically as a stain for free cholesterol in the study of Type C Niemann-Pick disease. ³ Filipin inhibits prion protein (PrP) endocytosis and causes the release of PrP from the plasma membrane. ⁴ Filipin III was found to trigger signaling responses in tobacco cells, including a NADPH oxidase-dependent production. ⁵. The antifungal mechanism of action may be due to altering membrane permeability and associated functions by binding to membrane sterols. Filipin inhibits prion protein (PrP) endocytosis and causes the release of PrP from the plasma membrane.

Other Notes

Filipin III solution is very sensitive to air and light. Upon receipt aliquot and store at -20°C avoid freeze thaw cycles. Filipin III is used in various concentrations depending on the specific protocol used. Dilute 1mg/ml stock solution with appropriate buffer according to the used protocol. Filipin III interaction with cholesterol alters the absorption and fluorescence spectra, for visualization with a fluorescence microscope use excitation at 340-380 nm and emission at 385-470 nm (Filipin fluorescent staining photo-bleaches very rapidly, thus the sample should be analyzed immediately).