Imaging of Proteoforms in Biological Tissues with High Spatial Resolution Using Nano-DESI Mass Spectrometry.

Abstract

Nanospray desorption electrospray ionization (nano-DESI) is an ambient mass spectrometry imaging (MSI) technique that enables molecular imaging of individual proteoforms in tissue sections. Nano-DESI generates multiply charged ions of intact proteoforms directly from the tissue, which facilitates their identification using on-tissue tandem mass spectrometry (MS/MS) and combined with database searching. We have developed an approach that enables imaging of proteoforms with a spatial resolution of 10 μm. In this chapter, we provide a detailed protocol for high-resolution imaging of proteoforms using nano-DESI MSI.