A typical workflow is: rapidly collect and fix (frozen or chemical fixation) to lock the in-situ distribution, then section (mainly frozen sections) to expose the cross-section, then apply matrix coating (MALDI) or conductive treatment (vacuum sources) as needed, then image. Matrix-free ambient sources (LDPI, DPI, DESI) can omit matrix coating and shorten the workflow chain.
Each step may introduce molecular migration, degradation, or artifacts, so the goal of workflow design is to achieve minimal disturbance with maximum fidelity, balanced with operability such as subsequent H&E/IHC annotation.
Core controls include: collection speed (to reduce post-mortem changes), fixation method (frozen favors small molecules, chemical fixation favors morphology), section thickness and temperature, and pre-processing uniformity (uniform matrix coating, complete conduction). Any loss of control will appear as artifacts or deviations in the image.
For small molecules and metabolites, ice-crystal damage and thaw migration must be especially suppressed; for proteins/peptides, enzymatic degradation must be prevented. Control points should be quantified and auditable.
Cross-sample and cross-project comparability in mass spectrometry imaging heavily depends on unified pre-processing. Establishing a standard SOP (unified reagents, parameters, operations, and quality-control checkpoints) minimizes human variability and is a prerequisite for cohort studies and reproducible science.
The SOP should also specify the data export format (such as imzML) and the registration workflow, enabling seamless integration between front-end preparation and back-end analysis.
Different sources have different preparation requirements: MALDI requires matrix coating, TOF-SIMS requires conductive slides, and LDPI/DPI/DESI are matrix-free ambient with the lightest preparation. The preparation plan should be adjusted to the chosen source rather than applied uniformly.
For a newly built matrix-free ambient imaging line, a short-chain SOP of frozen sectioning followed by direct sampling is recommended to maximize the retention of in-situ molecular information.
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).