Abstract: A method for the identification and localization of proteins or other biomolecules of a histologic tissue section comprises enzymatically digesting the biomolecules of two similar tissue sections while substantially preserving the biomolecule positions in the tissue sections. Next, a mass spectrometric image of the digest products in one of the tissue sections is acquired. Then, the digest products of the other tissue section are extracted and separated and the mass spectra and daughter ion spectra of all the digest products are acquired. A list of all identifiable biomolecules of the tissue section is created by comparing the mass spectra and daughter ion spectra with spectra in biomolecule structure databases or spectral libraries. Finally, the biomolecules in the list are assigned to digest products of the same mass in the mass spectra used to create the mass spectrometric image of the thin tissue section.

Abstract: A method for depositing samples, in which at least one sample (10) is arranged on a substrate (30), comprises the following steps: positioning a sample dispenser (20) above the substrate (30), and actuating the sample dispenser (20) so that the sample (10) is moved from the sample dispenser (20) along a trajectory (11) to a predefined deposition position (32) on the substrate (30), wherein at least part of the trajectory (11) is shielded against electrical interference fields. Also described is a substrate (30) for receiving samples (10), comprising a substrate body (31), on the surface of which at least one deposition position (32) is provided, and a shielding electrode (40), which is designed so as to electrostatically shield the space above the at least one deposition position (32) against electrical interference fields.

Abstract: A method for the identification and localization of proteins or other biomolecules of a histologic tissue section comprises enzymatically digesting the biomolecules of two similar tissue sections while substantially preserving the biomolecule positions in the tissue sections. Next, a mass spectrometric image of the digest products in one of the tissue sections is acquired. Then, the digest products of the other tissue section are extracted and separated and the mass spectra and daughter ion spectra of all the digest products are acquired. A list of all identifiable biomolecules of the tissue section is created by comparing the mass spectra and daughter ion spectra with spectra in biomolecule structure databases or spectral libraries. Finally, the biomolecules in the list are assigned to digest products of the same mass in the mass spectra used to create the mass spectrometric image of the thin tissue section.

Abstract: A method for depositing samples, in which at least one sample (10) is arranged on a substrate (30), comprises the following steps: positioning a sample dispenser (20) above the substrate (30), and actuating the sample dispenser (20) so that the sample (10) is moved from the sample dispenser (20) along a trajectory (11) to a predefined deposition position (32) on the substrate (30), wherein at least part of the trajectory (11) is shielded against electrical interference fields. Also described is a substrate (30) for receiving samples (10), comprising a substrate body (31), on the surface of which at least one deposition position (32) is provided, and a shielding electrode (40), which is designed so as to electrostatically shield the space above the at least one deposition position (32) against electrical interference fields.