Spatial metabolomics platform combining mass spectrometry imaging and in-depth chemical characterization with capillary electrophoresis
Leonidas Mavroudakis, Anastasia Golubova, Ingela Lanekoff
Abstract
Spatial metabolomics offers the combination of molecular identification and localization. As a tool for spatial metabolomics, mass spectrometry imaging (MSI) can provide detailed information on localization. However, molecular annotation with MSI is challenging due to the lack of separation prior to mass spectrometric analysis. Contrarily, surface sampling capillary electrophoresis mass spectrometry (SS-CE-MS) provides detailed molecular information, although the size of the sampling sites is modest. Here, we describe a platform for spatial metabolomics where MSI using pneumatically assisted nanospray desorption electrospray ionization (PA-nano-DESI) is combined with SS-CE-MS to gain both in-depth chemical information and spatial localization from thin tissue sections. We present the workflow, including the user-friendly setup and switching between the techniques, compare the obtained data, and demonstrate a quantitative approach when using the platform for spatial metabolomics of ischemic stroke. • A unique combination of MS imaging and surface sampling CE-MS on the same tissue • Mass spectrometry imaging enables spatial distribution of analytes over a tissue • Surface sampling CE-MS provides chemical characterization from a spot of interest • Isomer specific alterations due to stroke are to be pinpointed for the first time