Cell-to-cell chemical heterogeneity is a fundamental property of multicellular organisms.Subpopulations and rare cells can often be found even within presumably homogeneous cell populations.Capillary electrophoresis/mass spectrometry(CE-MS) is well suited to assaying the small molecules from selected cells and can provide a snapshot of a cell state.We combine CE-MS with patch clamp sampling to sample from select neurons and glia and relate the metabolomics profiles to electrophysiological state of the cells.[1-2] The approach is information rich but low throughput.