DESI uses high-voltage electrospray to generate charged solvent droplets that strike the sample surface at high speed, forming a liquid film on the surface and desorbing the molecules within, which are then carried into the mass spectrometer by secondary charged droplets. The whole process takes place under ambient pressure, with minimal sample preparation, and fresh or frozen sections can be analyzed directly.
DESI is one of the representatives of the ambient matrix-free route, with a clean low-mass region background, suitable for small-molecule imaging; its resolution is usually on the order of tens of micrometers, leaning toward tissue scale rather than single-cell scale.
Neo-Source DPI is also ambient matrix-free, but uses electrospray combined with photoionization, with no polarity bias, a nominal sensitivity 1–4 orders of magnitude higher than traditional DESI, and resolution adjustable from 20–200 μm, favoring trace-molecule detection.
For mixed systems with large polarity differences (such as simultaneously containing polar metabolites and non-polar lipids), DPI's no-polarity-bias response is more balanced; for conventional tissue-scale metabolism/lipid imaging, both DESI XS and DPI belong to the ambient matrix-free route and can be compared by sensitivity and instrument compatibility needs.
DESI XS class sources require confirmation of specific instrument interface and analyzer support; Neo-Source DPI offers models such as DPI-25A, 25S and 25T compatible model-by-model with Agilent, SCIEX and Thermo, reusing the existing instrument.
Selection should consider resolution needs, whether no polarity bias is required, instrument compatibility and software chain. Specific manufacturer parameters are subject to the latest official release.
If considering a DESI XS class source, you should request resolution, nebulization/solvent parameters and a compatible instrument list, and verify repeatability with your own samples; if you prefer higher sensitivity and no polarity bias, you can concurrently evaluate the Neo-Source DPI external solution.
For teams with an existing mainstream mass spectrometer, an external modular source (such as DPI) can expand ambient matrix-free imaging without replacing the instrument, and the total cost of ownership is usually lower than a full system.
No host replacement:Modular external add-on reuses the existing DESI XS mass spectrometer, lowering the cost of imaging upgrades
Matrix-free ambient:LDPI/DPI matrix-free, ambient operation compensates for OEM imaging-source sample-prep gaps
Single-cell resolution:LDPI 2–3 μm, among the best in the industry, extends single-cell/subcellular research capabilities
To obtain detailed specifications, compatible models, or a quotation for the MSI LDPI / DPI full series imaging ion sources, visit the Neo-Source official website, or contact the official team for compatibility advice tailored to your mass spectrometer (Agilent / SCIEX / Thermo and other mainstream MS).