Multivariate statistical analysis of electron probe microanalytical data on cell nuclear constituents.

A multivariate statistical analysis (the principal component analysis) has been used to process electron probe microanalytical data from cell nuclei. Fifty-seven measurements from different areas of chromatin and nucleolus in follicular rat cells have been studied. The variables are the X-ray characteristic signals for P, S, Al, Fe, Cu and Zn. This method demonstrates three groups of individuals - the chromatin area which is associated with a stronger concentration of P and two groups of nucleolar areas, one of them being connected with a higher content in S, Al and Zn. This high degree of correlation between these three elements proves the chemical affinity of the metals with the protein, S being the signature for proteins.

The occurrence of metals Al, Fe, Ni, Cu, Zn in the nuclei of animal cells: an ultrastructural, in situ, X-ray microanalytical study.

Cell nuclei may contain significant quantities of the metals Fe, Ni, Cu, Zn, since they are present in the nucleo-enzymes and/or nucleic acids. These metals have been detected by X-ray microanalysis in situ in dinoflagellates (Kearns et al). Aluminum was only detected in cell nuclei in cases of natural or provoked intoxication. We observed at the ultrastructural level, in situ, the presence of Al, Fe, Ni, Cu, Zn in nuclei of different types of non-intoxicated animal cells. Moreover, we measured the concentration of these metals in the nucleolus and chromatin and compared it with the concentration of P and S.