Journal Article

Mass spectrometry imaging with laser-induced postionization

Dreisewerd, Klaus, Vens-Cappell, Simeon, Soltwisch, Jens, Müthing, Johannes, Kettling, Hans, Wiegelmann, Marcel

2015

Overview

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can simultaneously record the lateral distribution of numerous biomolecules in tissue slices, but its sensitivity is restricted by limited ionization. We used a wavelength-tunable postionization laser to initiate secondary MALDI-like ionization processes in the gas phase. In this way, we could increase the ion yields for numerous lipid classes, liposoluble vitamins, and saccharides, imaged in animal and plant tissue with a 5-micrometer-wide laser spot, by up to two orders of magnitude. Critical parameters for initiation of the secondary ionization processes are pressure of the cooling gas in the ion source, laser wavelength, pulse energy, and delay between the two laser pulses. The technology could enable sensitive MALDI-MS imaging with a lateral resolution in the low micrometer range.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science
• Subject: Animals / Carbohydrates - analysis / Carbohydrates - chemistry / Cerebellum - chemistry / Desorption / Female / Gangliosides - analysis / Gangliosides - chemistry / Imaging / Ionization / Ions / Laser cooling / Lasers / Lipids / Lipids - analysis / Lipids - chemistry / Male / Malus - chemistry / Mass spectrometry / Membrane Lipids - analysis / Membrane Lipids - chemistry / Membranes / Mice, Inbred C57BL / Protons / Rats, Inbred Lew / Seminiferous Tubules - chemistry / Solubility / Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - instrumentation / Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods / Swine / Vitamins - analysis / Vitamins - chemistry