Anal. Chem. 2009, 81, 5858–5864
Capillary Electrophoresis with Electrospray Ionization Mass Spectrometric Detection for Single-Cell Metabolomics Theodore Lapainis, Stanislav S. Rubakhin, and Jonathan V. Sweedler* Department of Chemistry and the Beckman Institute, University of Illinois, Urbana, Illinois 61801 A method that enables metabolomic profiling of single cells and subcellular structures is described using capillary electrophoresis coupled to electrospray ionization time-of-flight mass spectrometry. A nebulizer-free coaxial sheath-flow interface completes the circuit and provides a stable electrospray, yielding a signal with a relative standard deviation of under 5% for the total ion electropherogram. Detection limits are in the low nanomolar range (i.e.,