The optimal deposition protocol for both positive and negative mode was found to be as follow: The saturated CHCA, SA, DHB matrices solutions (16 mg/mL for CHCA, 33 mg/mL for SA, 100 mg/mL for DHB) were prepared in wateracetonitrile (50/50 vol.). 5 µL nanoclusters solution (30 µM in 50/50 wateracetonitrile) was mixed with 10 µL saturated matrix under agitation (equivalent ratio 2:1). 1 µL of mixture was deposited to the groundsteel target with drying at ambient temperature.