title: Matrix vapor deposition/recrystallization and dedicated spray preparation for high-resolution scanning microprobe matrix-assisted laser desorption/ionization imaging mass spectrometry (SMALDI-MS) of tissue and single cells.
abstract: Matrix preparation techniques such as air spraying or vapor deposition were investigated with respect to lateral migration, integration of analyte into matrix crystals and achievable lateral resolution for the purpose of high-resolution biological imaging. The accessible mass range was found to be beyond 5000 u with sufficient analytical sensitivity. Gas-assisted spraying methods (using oxygen-free gases) provide a good compromise between crystal integration of analyte and analyte migration within the sample. Controlling preparational parameters with this method, however, is difficult. Separation of the preparation procedure into two steps, instead, leads to an improved control of migration and incorporation. The first step is a dry vapor deposition of matrix onto the investigated sample. In a second step, incorporation of analyte into the matrix crystal is enhanced by a controlled recrystallization of matrix in a saturated water atmosphere. With this latter method an effective analytical resolution of 2 microm in the x and y direction was achieved for scanning microprobe matrix-assisted laser desorption/ionization imaging mass spectrometry (SMALDI-MS). Cultured A-498 cells of human renal carcinoma were successfully investigated by high-resolution MALDI imaging using the new preparation techniques.
authors.affiliation: Institute of Inorganic and Analytical Chemistry, Justus Liebig University of Giessen, Schubertstr. 60, D-35392 Giessen, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Bouschen
authors.forename: Oliver
authors.initials: O
authors.lastname: Schulz
authors.forename: Daniel
authors.initials: D
authors.lastname: Eikel
authors.forename: Bernhard
authors.initials: B
authors.lastname: Spengler
mesh_terms: D002277:Carcinoma / Q000473:pathology; D045744:Cell Line, Tumor; D003460:Crystallization; D003584:Cytological Techniques / Q000379:methods*; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology; D010455:Peptides / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D010455:Peptides