Selective uptake of cholesteryl esters (CE) in rat ovarian granulosa cells as monitored with cholesteryl BODIPY® FL C₁₂ (Cat. No. C3927MP). The hormone-stimulated cells internalized and stored CEs derived from reconstituted high-density lipoprotein (HDL)–BODIPY® CE complexes (J Biol Chem 271, 16208 (1996)). A low-light (<100 µW beam power) computerized imaging system minimized any photobleaching of the fluorophore. This pseudocolored image uses yellow-green to illustrate the low-level fluorescence of the cytoplasmic membranes, yellow to illustrate the medium-level fluorescence of the Golgi, and red to illustrate the high-level fluorescence of the lipid droplets. Image contributed by Eve Reaven, VA Medical Center, Palo Alto, California.