Mass cytometry

Mass cytometry, however, has important limitations. First of all, the cells employed in the analysis cannot be recovered. Second, the potential huge number of labels complicates the analysis and data interpretation. Finally, the prize of the stable isotope conjugated monoclonal antibodies is quite high, also necessary to test their specificity, affinity, stability, and resistance (43). 

Mass cytometry uses stable isotopes as lanthanide series because of the huge number of elements of this family and their similar chemical structure, allowing their incorporation into the same tag (45,46). They also exhibit very low background due to their intrinsic low natural abundance (45-47). These rare earth elements are relatively biocompatible and easily conjugated to biomolecules by broad availability and simple protocols. Finally, they proffer high sensitivity for traces of molecules in biological samples, being attractive markers for their use in the clinical routine (47). 

Newell et al. analyzed human CD8+ T cells through mass cytometry in order to characterize surface biomarkers, cytokines, and antigen specificity with modified peptide-MHC. They have built a panel of 17 cell surface markers of human CD8 + T cells. They have also added nine additional markers six intracellular cytokines, CD107, two cytotoxic granule components, and the perforin and granzyme B. The samples were recollected from six healthy individuals and were stimulated to demonstrate their functional abilities. The analysis was carried out through principal component analysis. This group found that common definitions of naive, central memory, effector memory, and terminal effector subsets correspond to phenotypic clusters in their analysis. Moreover, they have found intermediate phenotypes that connect the clusters to form a continuum, but also exceptional cells that lead the classic definition (44). 

Leipod et al. have employed mass cytometry to characterize bacterial populations whose cell size is very small in comparison with mammalian cells... 

Bendall, S.C., Simonds, E.F., Qiu, P, El-ad, D.A., Krutzik, PO, Hnck, R. etoL (2011) Single-cell mass cytometry of differential immune and drug responses across a human hematopoietic continuum. Science, 332 (6030), 687-696. 

Management depends upon the underlying cause. The cardinal measurement, apart from the preliminary finding of a raised haemoglobin or haematocrit in the blood, is a separate determination of red cell mass and plasma volume using either flow cytometry or the traditional radonuclide methodology. 

Only recently, flow injection has been used as an interface to the first on-line application of flow cytometry [480]. Gorlach et al. [137] used flow injection for high throughput mass spectrometric mapping. 

Keywords. Vibrational spectroscopy, Mass spectrometry, Dielectric spectroscopy, Flow Cytometry, Chemometrics... 

The issue of distribution in the population of a monoseptic culture is only recently getting more attention. Studies on the single-cell level by image analysis (see the chapter in this volume by M.N. Pons), and by flow cytometry (see [4,5] and the section in the chapter by Sonnleitner in this volume), reveal that most microbial cultures are by no means a mass of identical cells, even those which do not show morphological inhomogeneity. Some of the methods discussed here can also give information on distribution of subpopulations, at least when these differ by clear-cut boundaries (for an overview see Table 2). 

Flow Cytometry Pyrolysis Mass Spectroscopy Enzyme activities by specific analysis or mRNA blot... 

Minor, E. C., and NaHathamby, P. S. (2004). Cellular versus detrital POM A preliminary study using fluorescent stains, flow cytometry, and mass spectrometry. Mar. Chem. 92, 9—21. 

As with flow cytometry, multiparameter apoptosis assays may also be performed by confocal laser scanning microscopy (CLSM). Using the approach similar to that detailed above for flow cytometry, we have examined NADPH content, mitochondrial membrane potential (CMX Rosamine fluorescence), and mitochondrial mass (Mitotracker Green), by CLSM. Figure 3 shows an example of a typical multiparameter assay performed by confocal microscopy. 

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