Patent ID: 8148676

Claim:
A method for studying protein expression in a tissue section, comprising: 1) applying an ionic MALDI matrix onto the tissue section, wherein said ionic matrix is solid at room temperature and selected from the group consisting of [CHCA − ANI + ], [CHCA − DANI + ], [CHCA − 2A4M5NP + ], [CHCA − 3APY + ], [CHCA − PDA + ], [SA − ANI + ], [SA − DANI + ], [SA − DIENI + ], [SA − Et3NH + ], [SA − PIP + ], [SA − 3AQ + ], and [SA − 3APY + ]; 2) scanning the tissue section with a MALDI mass spectrometer and saving the resulting data, and 3) in each analyzed point, determining the protein composition by comparing the obtained spectrum with database proteins molecular weights and spectra.