The phospholipid, Oregon Green 488 DHPE is labeled on the head group with the green-fluorescent Oregon Green fluorophore with excitation/emission maxima ∼501/526 nm. This fluorinated analog of fluorescein overcomes some of the key limitations of fluorescein, including greater photostability and a lower pKa (pKa ∼4.7 versus 6.4 for fluorescein), making its fluorescence essentially pH insensitive in the physiological pH range.