Abstract:
Seemingly uniform populations of a given cell type exhibit heterogeneity in their biomolecular composition. These differences can stem from genetic variations, but they can also be generated by the cell cycle, environmental factors, or disease states. Cellular heterogeneity is linked to drug resistance in infections and to low responders in the treatment of cancer. Analyzing single cells is a challenge because of their small volume and molecular complexity. Whereas genomic and proteomic analysis can be rendered by microarray technology and by mass spectrometry, respectively, the metabolic make-up of single cells is currently less accessible. We introduced two new ionization methods that enabled the identification of diverse metabolites directly from single cells. Laser ablation electrospray ionization (LAESI) is capable of detecting over 300 ionic species from large single cells [1]. Silicon nanopost arrays (NAPA), the first example of nanophotonic ion sources, can detect ~20% of the metabolites in the known yeast metabolome, and has the ability to analyze a single yeast cell [2]. This presentation focuses on applications of the LAESI and NAPA ionization methods to problems of biological relevance.
References:
1. B. Shrestha and A. Vertes, "In Situ Metabolic Profiling of Single Cells by Laser Ablation Electrospray Ionization Mass Spectrometry," Anal. Chem., 2009, 81, 8265.
2. B. N. Walker, J. A. Stolee, D. L. Pickel, S. T. Retterer and A. Vertes, "Tailored Silicon Nanopost Arrays for Resonant Nanophotonic Ion Production," J. Phys. Chem. C, 2010, 114, 4835.