Mass spectrometry imaging places strict demands on sample stability, especially when experiments run for hours at high spatial resolution. Vacuum-based sources often challenge matrix durability, as some compounds gradually back-sublimate and disappear from the tissue surface. This loss directly limits imaging performance.
Atmospheric pressure MALDI changes these constraints. Operating outside high vacuum conditions helps preserve matrix integrity and maintain sample stability across extended acquisitions. Long imaging runs become practical, with consistent signal quality over many hours.
The approach also influences ion behavior. Low-energy collisions at atmospheric pressure dissipate excess energy, which can improve molecular yield and reduce fragmentation for selected analytes. These effects support clearer spectral data and stronger confidence in molecular distributions.
The workflow introduces tradeoffs. Sample preparation demands tighter control, and small deviations from optimal protocols can impact results. Yet laboratories can prepare slides during the day, queue multiple tissue sections, and complete unattended overnight imaging runs, improving instrument utilization and productivity.
