Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Mass spectrometry imaging

Mass spectrometry imaging (also known as imaging mass spectrometry) is a technique used in mass spectrometry to visualize the spatial distribution of e.g. compounds, biomarker, metabolites, peptides or proteins by their molecular masses. Emerging technologies in the field of MSI are MALDI imaging and secondary ion mass spectrometry imaging (SIMS imaging).

SIMS Imaging
Secondary ion mass spectrometry (SIMS) is used to analyze solid surfaces and thin films by sputtering the surface with a focused primary ion beam and collecting and analyzing ejected secondary ions. SIMS imaging is performed in a manner similar to electron microscopy; the primary ion beam is rastered across the sample while secondary mass spectra are recorded.

MALDI imaging
Matrix-assisted laser desorption ionization can be used as a mass spectrometry imaging technique for relatively large molecules. In this version of the technique the sample, typically a thin tissue section, is moved in two dimensions while the mass spectrum is recorded.

DESI imaging
Other mass spectrometry ionization methods can also be used for MS imaging: for example desorption electrospray ionization.