HILL LAB RESEARCH Metabolomics by MALDI-IMMS

1. HILL LAB RESEARCH Metabolomics by MALDI-IMMS OVERVIEW MALDI-IMS-oTOF CONCLUSIONS Purpose:Two dimensional analysis of intracellular metabolites in Escherichia coli (E. coli). Method:E. coli metabolites were analyzed by MALDI-MS and MALDI-IMS-oTOF MS. Results: E. coli metabolites were resolved using MALDI IMS-MS. • The MALDI IMS-MS spectra shows the detection of ~800 E. coli metabolic features in the mass range of 50-3000 amu. • In the mass range 50-500 amu, ~200 metabolic features were observed in the MALDI IMS-MS plot while only ~60 were observed in the MS plot. • The E.coli metabolic features are resolved from the matrix in the MALDI IMS-MS spectra, whereas, the E. coli metabolic features are dominated by the matrix in the MS plot. • The MALDI-IMS-MS is a fast separation technique that is applicable for complex biological samples such as the E. coli metabolome. INTRODUCTION This project utilizes the novel approach for the separation and detection of metabolites in a complex biological system, such as E.coli, by using a MALDI-IMS-oTOF MS. The MALDI-IMS-oTOF MS has the ability to resolve the metabolite peaks from the background along with simultaneously separating metabolite isomers. The MALDI-IMS-oTOF MS is a promising method for determination of the metabolome in complex biological systems. RESULTS EXPERIMENTAL METHOD E. coli metabolites were extracted using methanol and spiked with ribitol as an internal standard. 2,5-dihydroxybenzoicacid was the MALDI matrix. A Voyager DE-RP MALDI-TOF mass spectrometer instrument at Washington State University was used for the MALDI-MS experiments. The MALDI-IM-oTOF system and its supporting electronics were designed and constructed at Ionwerks Inc. (Houston, TX). ACKNOWLEDGEMENTS This work was supported in part by a grant from the National Institute of Health-Road Map Grant #DK070274