Cell Sorting and Capturing

Laser capture microdissection was combined with MALDl-MS by several groups [49-52], In one study, the MALDl analysis of microdissected cells from human breast cancer in comparison to normal breast epithelial cells was reported [49], with more than 40 peaks in the MALDl mass spectra being found to differ in intensity between the cancer and normal tissues. This approach represents another way of achieving laterally resolved analytical information. In this case, it was not the focus size of the desorbing laser beam in the mass spectrometer. 

Background peaks (e.g., from matrix or sample support) are marked with asterisks. Reproduced with permission from Ref [48]. 2012 American Chemical Society. 

Opaque matrices are a methodological problem not only in the analysis of captured tissue cells but also in normal MALDl tissue imaging, when areas of interest must be positioned correctly after matrix application. Sweedler and coworkers have sought transparent matrices layers as substitutes for regular MALDl matrix substances [53]. The addition of triethylamine to solutions of standard MALDl matrices led to the formation of ionic liquids [54], and this was reported to result in favorable MALDl imaging performance. 

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