title: Gold-enhanced biomolecular surface imaging of cells and tissue by SIMS and MALDI mass spectrometry.
abstract: Surface metallization by plasma coating enhances desorption/ionization of membrane components such as lipids and sterols in imaging time-of-flight secondary ion mass spectrometry (TOF-SIMS) of tissues and cells. High-resolution images of cholesterol and other membrane components were obtained for neuroblastoma cells and revealed subcellular details (resolving power 1.5 mum). Alternatively, in matrix-enhanced SIMS, 2,5-dihydroxybenzoic acid electrosprayed on neuroblastoma cells allowed intact molecular ion imaging of phosphatidylcholine and sphingomyelin at the cellular level. Gold deposition on top of matrix-coated rat brain tissue sections strongly enhanced image quality and signal intensity in stigmatic matrix-assisted laser desorption/ionization imaging mass spectrometry. High-quality total ion count images were acquired, and the neuropeptide vasopressin was localized in the rat brain tissue section at the hypothalamic area around the third ventricle. Although the mechanism of signal enhancement by gold deposition is under debate, the results we have obtained for cells and tissue sections illustrate the potential of this sample preparation technique for biomolecular surface imaging by mass spectrometry.
authors.affiliation: FOM Institute for Atomic and Molecular Physics, Amsterdam, The Netherlands.
authors.forename: A F Maarten
authors.initials: AF
authors.lastname: Altelaar
authors.forename: Ivo
authors.initials: I
authors.lastname: Klinkert
authors.forename: Kees
authors.initials: K
authors.lastname: Jalink
authors.forename: Robert P J
authors.initials: RP
authors.lastname: de Lange
authors.forename: Roger A H
authors.initials: RA
authors.lastname: Adan
authors.forename: Ron M A
authors.initials: RM
authors.lastname: Heeren
authors.forename: Sander R
authors.initials: SR
authors.lastname: Piersma
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D001923:Brain Chemistry; D045744:Cell Line, Tumor; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008055:Lipids / Q000032:analysis*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*; D013261:Sterols / Q000032:analysis*; D013499:Surface Properties; D014667:Vasopressins / Q000032:analysis
chemical_list: D008055:Lipids; D013261:Sterols; D014667:Vasopressins; D006046:Gold