In situ synthesis of fluorescent membrane lipids (ceramides) using click chemistry

Ceramide analogues containing azide groups either in the polar head or in the hydrocarbon chains are non-fluorescent. When incorporated into phospholipid bilayers, they can react in situ with a non-fluorescent 1,8-naphthalimide using click chemistry giving rise to fluorescent ceramide derivatives emitting at ≈440 nm. When incorporated into giant unilamellar vesicles, two-photon excitation at 760 nm allows visualization of the ceramide-containing bilayers. This kind of method may be of general applicability in the study of model and cell membranes. Electronic supplementary material The online version of this article (doi:10.1007/s12154-012-0075-0) contains supplementary material, which is available to authorized users.