Time of Flight Mass Spectrometry Imaging of Samples Fractured In Situ with a Spring-Loaded Trap System.
Journal article, 2010

An in situ freeze fracture device featuring a spring-loaded trap system has been designed and characterized for time of flight secondary ion mass spectrometry (TOF SIMS) analysis of single cells. The device employs the sandwich assembly, which is typically used in freeze fracture TOF SIMS experiments to prepare frozen, hydrated cells for high-resolution SIMS imaging. The addition of the spring-loaded trap system to the sandwich assembly offers two advances to this sample preparation method. First, mechanizing the fracture by adding a spring standardizes each fracture by removing the need to manually remove the top of the sandwich assembly with a cryogenically cooled knife. A second advance is brought about because the top of the sandwich is not discarded after the sandwich assembly has been fractured. This results in two imaging surfaces effectively doubling the sample size and providing the unique ability to image both sections of a cell bifurcated by the fracture. Here, we report TOF SIMS analysis of freeze fractured rat pheochromocytoma (PC12) cells using a Bi cluster ion source. This work exhibits the ability to obtain single cell chemical images with subcellular lateral resolution from cells preserved in an ice matrix. In addition to preserving the cells, the signal from lipid fragment ions rarely identified in single cells are better observed in the freeze-fractured samples for these experiments. Furthermore, using the accepted argument that K(+) signal indicates a cell that has been fractured though the cytoplasm, we have also identified different fracture planes of cells over the surface. Coupling a mechanized freeze fracture device to high-resolution cluster SIMS imaging will provide the sensitivity and resolution as well as the number of trials required to carry out biologically relevant SIMS experiments.

Author

Ingela Lanekoff

University of Gothenburg

Michael Kurczy

Chalmers, Chemical and Biological Engineering, Physical Chemistry

Rowland Hill

Ionoptika Ltd.

John Fletcher

University of Manchester

John C Vickerman

University of Manchester

N. Winograd

Pennsylvania State University

Peter Sjövall

SP Sveriges Tekniska Forskningsinstitut AB

Andrew Ewing

University of Gothenburg

Analytical Chemistry

0003-2700 (ISSN) 1520-6882 (eISSN)

Vol. 82 15 6652-6659

Subject Categories

Chemical Sciences

DOI

10.1021/ac101243b

PubMed

20593800

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Latest update

9/6/2018 2