Atto 488 is a labeling dye with high molecular absorption (90,000) and quantum yield (0.80) as well as sufficient Stokes shift between excitation and emission maximum. It is optimized for excitation with an argon laser, and is characterized by high photostability.Atto-Dye Labeled PhospholipidsSigma-Aldrich offers a variety of glycero-phospholipids carrying one or two fatty acid groups (lipophilic groups) and a phosphate ester residue (hydrophilic group). They are labeled at the hydrophilic head group. After incorporation of the phospholipid into a membrane the fluorophore is located at the water/lipid interface of the membrane. We currently provide 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), palmitoyl-sn-glycero-phosphoethanolamine (PPE), and 1,2-dimyristoyl-snglycero-3-phospho-ethanolamine (DMPE) labeled with Atto-dyes.find more information here