Deep-ultraviolet Laser Ablation Sampling for Mass Spectrometry
Remilekun O. Lawal; Fabrizio Donnarumma; Kermit K. Murray
High resolution sampling of biological systems is crucial to revealing the differences in proteins and metabolites amongst heterogeneous cells. Laser ablation sampling for mass spectrometry is a powerful method for analyzing biomolecules in tissue under ambient conditions with high spatial control while eliminating the need for external matrices. It allows off-line analysis by liquid chromatography tandem mass spectrometry and can be combined with mass spectrometry imaging for region of interest selection. The most efficient lasers currently used for ablation sampling use mid-infrared wavelengths that are diffraction limited to spot sizes tens of micrometers in diameter. Short wavelength lasers can be focused to order of magnitude smaller spot sizes for efficient ablation with minimal thermal damage to adjacent sample areas.