Lipophilic fluorescent cell staining probe contains a C12 alkyl chain that will bind to membranes with the fluorophore at the aqueous interface and the alkyl tail protruding into the lipid interior. Useful to label plasma mebranes. Binds strongly to amphiphilic block copolymer micelles. Useful for determining the critical micelle concentration (CMC) of various detergents based on fluorescence polarization (anisotropy). Lipophilic fluorescein probes are commonly utilized for fluorescence recovery after photobleaching (FRAP) measurements of lipid lateral diffusion. Used for visualization of proteins in 1-D and 2-D SDS-PAGE gels. Spectral data: lambdaex=490nm, lambdaem=520nm.