Traditional reflection MALDI enters the laser from the same side of the target, and some ions fly backward and are lost; t-MALDI enters the laser from the back, and desorbed molecules and ions are mainly emitted toward the analyzer, so more ions are collected, improving effective yield and signal-to-noise.
This geometry also favors finer laser focusing and uniform sampling, one of the physical bases for t-MALDI reaching higher spatial resolution.
With optimized laser and scanning, t-MALDI can push MALDI imaging resolution to sub-micron to micron levels, better than conventional reflection mode, suiting tissue imaging needing finer pixels. It works notably well with high-resolution analyzers (TOF, Orbitrap).
Note: resolution gains are still constrained by matrix crystallization, scan step, and preparation fidelity; subcellular needs often still require dedicated high-resolution sources such as TOF-SIMS.
t-MALDI is mostly done under vacuum (vacuum MALDI family), differing from AP-MALDI (ambient MALDI) in pressure environment; both share the matrix-assisted desorption basis. t-MALDI's advantage is ion yield and resolution, AP-MALDI's is ambient-operation convenience.
Selection should weigh resolution, throughput, and sample state: choose t-MALDI for high resolution, AP-MALDI for ambient flexibility, and LDPI/DPI for matrix-free.
t-MALDI still relies on matrix, with small-molecule matrix interference; for small-molecule/metabolite imaging it can be compared with matrix-free sources (LDPI, DPI). For large-molecule, high-resolution MALDI imaging, t-MALDI is a mature preferred choice.
It is advised to select by target-molecule scale and resolution needs, with matrix-spray uniformity as a key quality control.
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).