Unique to the SYNAPT XS, Full Spectrum Molecular Imaging (FSMI) represents a combination of advanced Mass Spectrometry (MS) imaging technologies, integrating DESI, MALDI, and ion mobility mass spectrometry through a dedicated imaging informatics solution. Waters’ FSMI system provides detailed molecular information that exceeds any single MS imaging technique currently available, delivering high quality, comprehensive, spatially resolved molecular information across a variety of application areas, and with the minimum of time and effort.
Enhance your MS imaging capabilities
The FSMI system solution has been enhanced, both with the introduction of the state-of-the-art HRMS ion mobility-enabled mass spectrometer, the SYNAPT™ XS, and the introduction of the new and improved DESI™ XS source. In addition to this, we have responded to customer need by improving the Waters High Definition Imaging (HDI) Software with advances in data processing speed for large data sets, improving data alignment for HDMSE data and removing limits on the amount of data that can be processed and loaded into the software.
Full Spectrum Molecular Imaging is only available on the SYNAPT family HD-enabled MS system solutions. These systems can also used as standard ESI-Tof instruments for other UPLC-MS based applications by easily changing system configuration.
Access deeper information through complementary molecular visualization
FSMI DESI and MALDI analyses present different molecular ionization on the same tissue surface, and therefore complementary images detailing molecular spatial localization. An example here is shown on the cortex and the medulla of the kidney. Black spectrum areas have been magnified in the MassLynx™ spectrum view. Red and green spectra are from the medulla and the cortex of the kidney respectively. These images highlight different lipid profiles which are only possible to visualise via either DESI or MALDI analysis. It also emphasizes that that small molecules such as metabolites are more easily detected with DESI than MALDI.
Increase molecular coverage with complementary ionization capabilities
MS Imaging peer reviewed publications acknowledge the complementary nature of FSMI and have shown methods and workflows for complete comparison between the techniques, accounting for intra-technique variables such as polarity, MALDI matrix, and DESI solvent system.¹
The opposite image is a summary of the screening results of a panel of 24 pharmaceutical compounds analyzed by DESI and MALDI on a SYNAPT mass spectrometer, highlighting the intensity of compounds which were detected at 1 ng on glass slide in: A) positive mode, B) negative mode, C) positive and negative modes combined. In purple, same level detected with MALDI and DESI. In red, better detection with MALDI. In blue, better detection with DESI.3
The relative benefits of applying MALDI and DESI
The speed and versatility of DESI imaging make it most amenable to the analysis of lipids and other small molecules under its favorable ambient, direct analysis conditions. MALDI imaging can favor the detection of proteins and peptides and has the advantage of a higher spatial resolution, but requires higher instrument pressures and sample preparation.
The combination of the two techniques on a single platform covers a wide range of applications and compound classes with speed and ease. In the figure opposite, the green text displays the relative advantages of each approach.
Discover new and exciting possibilities for your research with Full Spectrum Molecular Imaging. Take a look at the resources below to get started.
1. Anal. Chem. 2018, 90, 9, 5637-5645 Exploring Ion Suppression in Mass Spectrometry Imaging of a Heterogeneous Tissue. Date: February 20, 2018 https://doi.org/10.1021/acs.analchem.7b05005
2. Waters Application Note 720005947en. DESI-Mass Spectrometry Imaging Investigation of Discrete and Cassette Drug Dosed Tissues.
3. Evaluation of the Ionization Efficiency Between MALDI and DESI MSI for the Analysis of Pharmaceutical Compounds, 2018 poster. Emmanuelle Claude and Mark Towers.