IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Applied Surface Analysis Monday Sessions
       Session AS-MoP

Paper AS-MoP10
TOF-SIMS and Laser-SNMS Characterization of Cell Cultures and Tissue Material

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Student Poster Competition/Aspects of Applied Surface Analysis I Poster Session
Presenter: M. Fartmann, Universität Münster, Germany
Authors: M. Fartmann, Universität Münster, Germany
S. Dambach, Universität Münster, Germany
A. Wittig, Universitätsklinikum Essen, Germany
W. Sauerwein, Universitätsklinikum Essen, Germany
H.P. Wiesmann, Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie Münster, Germany
H.F. Arlinghaus, Universität Münster, Germany
Correspondent: Click to Email
In medical and pharmaceutical research, knowledge of the distribution of drugs and intrinsic elements and molecules in tissue sections and even inside individual cells is of great interest. We have applied TOF-SIMS and Laser-SNMS for imaging and quantifying atomic and molecular species in biological samples. Both techniques can simultaneously detect all masses with very high sensitivity and sub-cellular resolution. Since most of the sputtered particles are neutrals, Laser-SNMS has the additional advantage of significantly reducing the matrix effect. To prepare cell cultures for mass-spectrometric analysis, a freeze-fracturing method was used. Hereby the cells are sandwiched between two substrates before being frozen. This sandwich is then pried apart in its frozen state, so that some cells are torn. Subsequently, the samples are freeze-dried. The fractured cells can then be examined with TOF-SIMS and Laser-SNMS. Successful sample preparation is characterized by the distribution of the Na/K ratio. We have used TOF-SIMS and Laser-SNMS to examine freeze-fractured, freeze-dried bone and cancer cell cultures and freeze-dried cryosections of bone tissue. For analysis, a gridless reflectron-type TOF mass spectrometer with a 30 keV Ga LMIG and an excimer laser was used. For nonresonant postionization, the excimer laser beam (wavelength = 193 nm) was focused down in front of the target. With both techniques, high resolution elemental and molecular images and mass spectra were obtained from cell cultures and tissue samples. Ion-induced electron images were obtained to identify individual cells. The measurement of the Na/K ratio clearly showed that the preparation technique preserves the chemical und structural integrity of the cells. It can be concluded that TOF-SIMS and Laser-SNMS are well suited for imaging trace element and molecule concentrations in biological tissues.