Molecular identification using high-sensitivity tandem mass spectrometry is essential for protein analysis on the tissue surface. Here we report an improved digestion protocol for protein identification directly on the tissue surface using mass spectrometry. By denaturation process and the use of detergent-supplemented trypsin solution, we could successfully detect and identify many molecules such as tubulin, neuro. lament, and synaptosomal-associated 25 kDa protein directly from a mouse cerebellum section. (C) 2008 Elsevier B.V. All rights reserved.