O. Orwar, H. A. Fishman, N.E. Ziv, R.H. Scheller, and R. N. Zare, “Use of 2,3-Naphthalenedicarboxaldehyde Derivatization for Single-Cell Analysis of Glutathione by Capillary Electrophoresis and Histochemical Localization by Fluorescence Microscopy,” Anal. Chem. 67, 4261-4268 (1995).