This product is a high purity, non-natural L-threo ceramide containing a fluorescent NBD label and is ideal as a standard and for biological studies. NBD (7-nitrobenzofurazan) has been shown to have only a small influence on lipid adsorption into cells and cellular membranes especially when the fatty acid is a short chain. The fluorescent analog of natural ceramide is comparable to C6:0-ceramide in many biological functions such as inhibition of VSV-G protein transport1, and transport of sphingomyelin and glucocerebroside from the golgi apparatus to the cell surface.2 Both the natural D-erythro and the nonnatural L-erythro and the D- and L-threo ceramides display similar effectiveness in inducing apoptotic damage in cells.3 The protein phosphatases PP1 and PP2A, which are involved in regulating apoptosis and cell growth, are activated by D-erythro ceramide but inhibited by L-threo, D-threo, and L-erythro ceramide.4 Both D-erythro and D-threo C2 ceramides have been found to be potent inducers of IL-6 production, while neither the L-threo or L-erythro stereoisomers of ceramide were effective.5 D- and L-erythro ceramide and D- and L-threo ceramide are also comparably effective inhibitors of protein kinase C.6