What do we do?
The Sampling & Separation Core devotes significant effort to aspects of directed sampling of the brain. While not normally considered a typical proteomics effort, the ability to target a single cell, or a small numbers of cells, for direct mass spectrometric analysis has revolutionized neuropeptide detection over the last ten+ years, with more than 350 new neuropeptides being characterized using this approach, perhaps more than any other proteomics approach during this same period.
The selection of appropriate samples, ranging from intact brains to single cells, will be decided between Center staff and the participating biological scientists. The Center offers precise sample collection, using either cell isolation or laser capture microdissection. The Sweedler group is developing microfluidic and generalized affinity sampling methods, as well as array sampling approaches, that allow the collection of cell releasates and more precise sampling under particular situations. These samples are then carefully conditioned and fractionated using electrophoretic or chromatographic processes to prepare them for mass spectrometric analysis.
Patch Clamp Electrophysiology and Capillary Electrophoresis–Mass Spectrometry Metabolomics for Single Cell Characterization, J.T. Aerts, K.R. Louis, S.R. Crandall, G. Govindaiah, C.L. Cox, J.V. Sweedler, Anal. Chem. 86, 2014, 3203–3208. DOI:10.1021/ac500168d
Small-Volume Analysis of Cell-Cell Signaling Molecules in the Brain, E.V. Romanova, J.T. Aerts, C.A. Croushore, J.V. Sweedler, Neuropsychopharmacology 39, 2014, 50–64. DOI:10.1038/npp.2013.145
Qualitative and Quantitative Metabolomic Investigation of Single Neurons by Capillary Electrophoresis Electrospray Ionization Mass Spectrometry, P. Nemes, S.S. Rubakhin, J.T. Aerts, J.V. Sweedler, Nat. Protoc. 8, 2013, 783–799. DOI:10.1038/nprot.2013.035Mass Spectrometry Imaging and GC-MS Profiling of the Mammalian Peripheral Sensory-Motor Circuit, S.S. Rubakhin, A. Ulanov, J.V. Sweedler, J. Am. Soc. Mass Spectrom., 2015, E-pub ahead of print. DOI:10.1007/s13361-015-1128-8