Mass spectrometry imaging can provide information on the spatial organization of chemical components in cells and tissues. Researchers probe a particular region by laser ablation, then analyze the ions produced. Colorado State University scientists have devised a one-of-a-kind instrument that lets them map cellular composition in unprecedented 3D resolution (1).
The device uses a laser that emits pulsed extreme ultraviolet (EUV) light at a wavelength of 46.9 nm. “The uniqueness of our approach resides in the fact that most materials are highly absorbing at 46.9 nm,” explain researchers Ilya Kuznetsov and Carmen Menoni. “Therefore, the radiation can be confined to nanometer-thick layers and the beam focused to spots 1,000 times smaller than the diameter of a human hair” – about 100 times more detailed than was previously possible. The image shows an isolated Mycobacterium smegmatis bacterium imaged in five passes and post-processed to produce smoothed profiles of each molecule’s distribution inside the bacterium. For example, the 91 m/z ion (blue) shows similar distribution in all five layers, while the 86.1 m/z ion (green) varies widely. With improved sensitivity and extended mass range, the EUV laser ablation mass spectrometer may provide increasingly detailed information on the subcellular chemical organization of lesions and microorganisms.
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References
- I Kuznetsov et al., “Three-dimensional nanoscale molecular imaging by extreme ultraviolet laser ablation mass spectrometry”, Nat Commun, 6, 6944 (2015). PMID: 25903827.
