Mass spectrometry imaging (MSI) is a novel molecular imaging technique that can directly obtain the structure, content and spatial distribution information of a large number of known or unknown molecules such as endogenous metabolites and exogenous drugs from biological tissues. Compared with other imaging methods (e.g. fluorescence imaging, radiolabeled imaging, etc.), this technique does not require chemical or radiolabeling, complex sample pre-treatment. It has the advantages of high specificity, high throughput and spatial information retention.
Fig 1. Steps of a typical data analysis workflow in imaging mass spectrometry (Alexandrov, 2020)
MSI technology enables qualitative, quantitative and localization analysis of thousands of metabolites in biological tissues. Combined with bioinformatics analysis, it has been developed into a spatial metabolomics approach that allows the discovery of differential metabolites from biological tissues in situ and the identification of their biological functions.
Spatial metabolomics has been further upgraded from desorption electrospray ionization mass spectrometry imaging (DESI-MSI) technology to aerodynamically assisted ionization desorption electrospray ionization mass spectrometry imaging (AFAI-MSI) technology. The charged droplets are transported over long distances using air flow with a transfer tube. The charged droplets in the transfer tube are further desolvated, enriched, and ionized by the high-speed airflow and voltage, which subsequently improves detection sensitivity while expanding the space and operational flexibility of the sample to be measured. It is suitable not only for single tissue samples, but also for long-distance ion collection and imaging analysis of large volume samples.
Creative Proteomics can provide you with spatial metabolism services, offering you new perspectives and accelerating the progress of your project.
Fig 2. An imaging mass spectrometry (MS) dataset represents a collection of spectra acquired from a raster of pixels representing the surface of a tissue section (Alexandrov, 2020)
Samples that can be analyzed include but are not limited to
- Mouse/Rat: Brain, kidney, heart, liver, spleen, spinal cord, pituitary, pancreas, skin, whole mouse/rat.
- Tumor tissue: esophageal cancer, thyroid cancer, lung cancer, breast cancer, stomach cancer, glioma, nasopharyngeal cancer, skin cancer, liver cancer.
- Plant tissues: root, seed.
Process of Spatial Metabolomics Technology
1）A certain high voltage is applied to the electrospray capillary nozzle, the spray solvent flows out from the inner casing of the atomizer, and the high pressure nitrogen gas emitted from the outer casing rapidly atomizes the spray solvent to form charged spray droplets.
2) The sprayed high speed charged droplets bombard the surface of the sample to be measured, and the sample is desorbed and ionized at the same time under the effect of solvent extraction.
3) The charged droplet containing the sample under test is rapidly desolvated and enters the analyzer through the collection cone of the mass spectrometer and is detected.
4) The sample is fixed to the carrier platform and the sample is scanned in two dimensions by moving the carrier platform continuously or pulsed.
5) The mass spectrometer records the intensity of the mass spectral signal to obtain the molecules and their content on the sample surface.
6) This information is converted by mass spectrometry image analysis software to obtain a two-dimensional spatial intensity distribution map of selected ions or ion populations.
Creative Proteomics will work with you to customize a solution to meet the specific needs of any project. If you have additional needs or questions regarding metabolomics analysis, you can contact us and one of our technical staff will communicate with you.
- Alexandrov, T. (2020). Spatial metabolomics and imaging mass spectrometry in the age of artificial intelligence. Annual review of biomedical data science, 3, 61-87.
For Research Use Only. Not for use in diagnostic procedures.