University of Regensburg Trenner Faculty of Chemistry Trenner Analytical Chemistry
Bioanalysis and Biosensors

Chemical Analysis of Animal Cells by Mass Spectrometry

Analysis of Animal Cells

Animal cells are chemically analyzed using a dual beam secondary ion mass spectrometer. A Bi-cluster ion source is used to generate secondary ions of the sample surface which are analyzed in a time-of-flight mass analyzer. Scanning the sample with the focused ion beam generates a 2D chemical image of the sample surface. A second ion source is used to erode the sample in between two subsequent imaging cycles. Sputter erosion removes a thin layer of the organic material ( app. 20 nm) and exposes a new, inner surface of the sample. Subsequent cycles of sputter erosion and chemical surface imaging generate a 3D image of the cell providing chemical contrast. The intensity images shown on the right are color-coded as follows: red - amino acid fragments; green: membrane fragments; blue: fragments of the growth substrate. Images a, b,c and d show the lateral distribution (xy) of the respective secondary ions in a certain depth within the sample. Image f provides a side view on the sample and, thus, distribution of chemical species perpendicular to the sample surface (xz).

This project is pursued in close cooperation with Tascon GmbH, Münster.


© 2008, Thomas Hirsch, Gisela Emmert.